CORE’s Passion Remains Unchanged

To Enhance the Lives of Our Clients and Team

If you’re a business owner with a cash flow problem, Core Group can help. We have a proven process that we will take you through step by step to put more money in your business and less in your taxes.


Meet Our Business Experts

Christian Brim

"I graduated from the University of Oklahoma with a Bachelor of Accountancy. I enjoy spending time with my wife and three children, and the very occasional golf game. In addition to firm administration, I handle Business Advisory services and business succession planning for our clients. Mostly, I enjoy watching our clients successfully grow their businesses."

Nathan Brim

I have a passion for small business. I enjoy helping other achieve their goals and I love to see our clients and our team prosper. I started in our Oklahoma City office in 2002 and did every job in our office (bookkeeper, payroll processor, telemarketer, manager, outside sales, and admin) at some point. I did some of those positions well and others I did poorly but I learned a lot about the operations of the business. I moved to Tulsa in 2003 to open our second location and assumed all of those roles mentioned above since I was a one-man office! Currently, I concentrate on our firm administration and making sure that our team is successful in providing services to our client. I also provide business consulting and financial services to our clients. I am a problem solver by nature and enjoy new challenges on a daily basis. I have been married since 2005 and have a son and a daughter. Our family loves to travel and are constantly looking for new adventures! I am a golfer who doesn’t get out as much as I would like and am always looking for a reason to be on the course. I am an active member of the Entrepreneur’s Organization and I am a continual learner. What was the last book you read cover to cover? Why did you read it? What did you learn from it? Would you recommend it to others?  “The Power of Moments” I like meaningful connections with people – yes, I would recommend it.

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Alicia Brooksher

Alicia Brooksher joined Core Group in November of 2010 as a Jr. Payroll Specialist. Prior to coming to work for Core, her background is in administrative support. When she is not working she enjoys spending time with her husband and young son. In her spare time she enjoys scrapbooking, going to car shows and watching her husband race the quarter mile. My favorite movie of all time is: The Wizard of Oz

Gloria Dattolo

I joined Core Group in May of 2019, as a bookkeeper. I have graduated from the University of Malta with a Bachelor of Commerce (Hons) in Banking and Finance. I have worked in many different fields but always had a passion for accounting. I hail from the tiny island of Malta and moved to the US in 2005. I enjoy spending time with my son, painting and dancing. Travelling is also another interest of mine in which I do not engage in as often as I used to.

shelli-tulsa business consulting | tulsa accounting | lawton financial services | oklahoma city accounting
Shelli Dixon

I started my first payroll job in 1996 while in college and graduated from East Central University with a bachelors in Business Administration. I joined Core in the payroll department in 2007. I love what I do and enjoy helping small businesses with their payroll issues and problem solving. When not working I enjoy spending time with my family and friends. I have been married for 16 years and we have 2 wonderful children. If you had the option to live in any period in history, what era would you select and why? The 50’s - poodle skirts, the cars and the Soda Shoppes, life seemed easy.

Jeremy Doorn

I graduated from the University of New Mexico in 2001 with a bachelors in Business Administration. I moved to Tulsa in 2007 and started working at Core in 2009. I do a little bit of everything at the office from bookkeeping to managing client relationships. On the weekends, I enjoy watching just about any sport that is on TV, especially basketball and football. Also, I enjoy playing music (drummer) and golf with my friends and spending time with my lady. Think of 3 things about yourself you like the best: I am funny, hardworking and smart.

DaRenda Hanson

In my free time…oh, wait…I’m married with two children.  I don’t have free time.  I was born and raised in Oklahoma and bleed crimson and cream through and through.  On my first date with my husband I asked him a simple question, “OU or OSU?”  Lucky for him, his answer was “OU.”  He still doesn’t believe me that we wouldn’t be married today if he had answered the latter. We’re raising two boys and a golden retriever.  If you have any tips for raising either of these, I’ll gladly take them.  They’re teaching me to be a little more patient, one day at a time. I am a homebody.  I’m usually the person that makes plans with friends, then the day before we’re supposed to go I confess to my husband that I don’t want to go.  I’m a creature of habit and I love routine. I’m kind of a DIYer, but mostly just independent and a penny pincher.  I research to a fault, I research a projects (to DIY) for so long that I’ll talk myself out of even doing it. I don’t like cheesecake. I don’t like pumpkin pie. I want to be skinny, but I also want to eat all the chocolate. I want to make more time in my life to volunteer for the causes that are close to my heart, mostly having to do with foster children. I’m more of an Amazon Prime mom than a Pinterest mom. I love Google. Sweet Tea is delicious. I said I’d never drive a minivan, but I do.  Those sliding doors are amazing when you have kids!

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Jeff Henderson

"I've worked here as an accounting manager since 2003. My responsibilities are providing financial statements, tax return preparation and general business consultation to our clients. As a financial professional for over 30 years it is very rewarding to me to be able to share my expertise and experience. My wife is a registered nurse and we enjoy traveling and being with our children and grandchildren." If you magically had 2 more hours every day, how would you spend the extra time? Sleeping

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Jennifer Herrs

I came to Core in May 2012, I enjoy partnering with clients to build lasting relationships that benefit them both professionally and personally.  My true passion is documenting processes and working to find the best way to get things done. I grew up playing competitive softball and spending as much time as possible on my grandparents farm. My husband and I live on 20 acres with our 3 children, cats, dogs and small herd of cattle. What photograph means the most to you. Describe the photo and why it is so powerful: It’s not a photo, it’s a drawing. When I was in college my Grandpa (PaPa) made a drawing for me. He included cows and a coyote. My Papa and I are very close. (He just turned 89)

Anita Heyd

I am from OKC and went to Moore Schools for 12 years. I am happy to be a part of the Core Family and look forward to coming to work every day because I enjoy the people I work with in the office as well as the many clients I get to talk to on the phone and in person. I have been married to a Great Guy for 48 years … we have 1 daughter, 1 dog  (Mr. Monk) and many fish. If I can help you in anyway please let me know, it will be my pleasure. I will eat anything put in front of me except: offal of any kind

Sabrina Holloway

I joined Core in June 2011 as the Tulsa bookkeeper. I am responsible for all of the Tulsa client’s monthly bookkeeping, as well as a few Oklahoma City clients. I am also the tax processor in Tulsa and I perform a variety of administrative duties around the office as well. I enjoy assisting my clients on a daily basis with any questions they may have and learning about the many different types of businesses that we work with, as well as getting to know all of our clients. I enjoy bookkeeping and love Core as a company and plan to be here for a very long time. Prior to Core, I worked for Bank of Oklahoma for 6 years, starting as a teller and spending the last 3 years there as an Assistant Branch manager. Math was always my favorite subject in school and I knew that one day I would end up in the financial industry. When I am not at work, I love spending time with my family and friends. I am married and we have a beautiful daughter. We love to travel, ride bikes, and play games. What was the last book you read cover to cover? Why did you read it? What did you learn from it? Would you recommend it to others?  “Girl Wash Your Face” – for Book Club – I felt I could relate – Helped me realize that other people struggled with the same things in life.  

Elizabeth Long

I am passionate about helping people and genuinely enjoy building relationships with my clients.  I grew up in my mother’s accounting office and always knew Public Accounting was my calling.  My family and I made the move to Oklahoma from Maryland in 2017. We made the journey with my two horses, dogs, fish, and four children.  We continue to expand our farm and I enjoy caring for all of our animals. The whole experience of moving and growing our small homestead has been extremely rewarding.  I enjoy horseback riding, crafting and reading. If you could be a character in a book or novel, who would you be and why? Anita Blake “Vampire Slayer” – because she kicked butt

Shelley Nowlin

I joined the Core Family March 2013. I have been doing payroll since 2007, starting with a large payroll company. I enjoy working for a small company doing payrolls for other small businesses. I look forward to helping my clients with the tough payroll questions. When not working I enjoy spending time with family and friends and of course my cats. Also enjoy cross-stitch and quilting, one of my best memories is hand quilting with my Grandmother. We did quilts for each of her 7 children and one for me. If you could be a character in a book or novel, who would you be and why? – Harry Potter – he may not always do the right thing but he always tries.

Belinda Osborne

I was born and raised in Oklahoma. I received my BA from Cameron University in Lawton, OK. I have worked in sales and/or accounting for over 30 years. I’ve been with Stanfield & Brim almost 2 years and thoroughly enjoy working with the Lawton, Ft. Sill community. Our clients are very important to me and our team. That’s one of the really good things about this job – our team knows how to work together to get things done. On a personal note, when I’m not working, my husband, three sons and I enjoy traveling and golfing. My youngest son plays the North Texas and Oklahoma PGA tournaments. As a child, my favorite game was: Basketball

Chelsea Powers

I joined Stanfield & Brim in March of 2017 as a client relations manager. I graduated from Cameron University with a Bachelor’s of Accounting. I have a variety of experience in the field including tax preparation, bookkeeping, and audit work. I was raised right here in Lawton and prefer to spend my free time out hiking in the mountains or paddle boarding on the lakes with my family. I also enjoy traveling and hope to one day make it to Finland and stay in one of their Igloo Villages to see the Northern Lights. If you had one wish that was guaranteed to come true, what would you wish for and why? To live in Medicine Park on Big Rock Road – because it is beautiful.

Lynda Ramming

"I am a CPA with 23 years of experience, 17 of which I worked for Stanfield & O'Dell, P.C. (now Stanfield & Brim). My primary focus had previously been in the audit area; but I have more recently focused on tax return preparation, reviews, and compilations. I currently work as a seasonal employee, only during tax season. I was born and raised a Lawtonian, and born and bred a Sooner. During the 'non-tax season' part of the year, I help my family run their gift and clothing stores. I have been married for sixteen years. My husband and I both enjoy traveling, cooking, and spending time with family and friends." My favorite movie of all time is: Grease

Dawn Seay

I have worked for Core Group since November 1, 2001 as a bookkeeper. I became a Certified Bookkeeper in December, 2014 and enjoy working with our diverse clientele, learning about different types of businesses and helping take stress and worry from business owners by doing what I love to do. My husband Andy and I got married in 2013 and enjoy bowling and working in our yard in Oklahoma City. Share something mischievous you did as a child: Blackmailed my brother

Darryl Turnbull

"I am a CPA and had my own practice prior to joining CORE. In 2009 I merged with Stanfield & Brim PC and my staff and I became part of the CORE family. I have a BS in Accounting, but also have 10 years of experience in manufacturing and production as an operations manager. That practical experience helps me to understand the challenges that my clients face in managing their business each day. I enjoy being able to help clients find ways to increase profit and better understand the costs related to business decisions. It is the most satisfying part of the work I do. I am married and have 4 children: 1 twenty-one and 3 eighteen year olds yes...triplets. I've been scuba diving since 1979 and I am still amazed by the peace and tranquility that you can find floating in that other world. I have been golfing twice in my life and managed to not hurt anyone, but I know I'll never have the time and patience to be any good at it so I don't torment myself. Away from the work enjoy cooking and entertaining friends and family, traveling and camping. I am a life-time member of the Sooner Nation and love college football. I cheer for OU and anyone playing against Texas." Imagine that you could go back in time and change one decision in your life. Which one and why?  I was offered a job going to Alaska to be a sound engineer on a documentary and I turned it down. I missed the experience.

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