Meet Our Team

Affordable Payroll and Bookkeeping Services

Serving Petaluma, Santa Rosa, Sebastopol, Novato, Sonoma County, the North Bay and remotely serving the entire United States

Hello. Lovely to meet you! We pride ourselves on knowing our clients and their business. Your financial health excites us and we enjoy watching your business grow. While our work life is of the utmost importance, we also wanted you to know a little bit about us as people. We are involved in our community, and we are vacation enthusiasts. We have our own quirks, likes and dislikes. Each of us is skilled, driven and invested in the prosperity of your business. Let us know a little about you and your business as well. CONTACT US or give us a call at (707) 763-5990.

Caring about YOUR business is OUR business.


Barbara Thornton founded ABBA in 1987. Over the years she has helped hundreds of clients set up their books as the foundation to a thriving business. Barb most enjoys challenging work, something that resembles a giant puzzle. She likes separating out the pieces to see how it all fits together. Barb takes pride in creating a proper audit trail that will stand up to any auditor’s review. Over the years, Barb has mentored many individuals in bookkeeping, accounting and business practices. She is passionate about empowering other bookkeepers to reach their potential and achieve their dreams in creating their own business environment.

In her spare time Barb enjoys a variety of activities. She enjoys the warmth of the summer sun, especially on a cool fall day surrounded by the colors of the season. She loves visiting Caribbean blue waters and white sandy beaches, and unplugging from the daily grind. Barb is fond of singing and does so regularly with a choir. She relishes long walks with her dogs and celebrating life with those she holds near and dear to her heart.

"I’m still working for Smothers. I’m always so thankful to you for taking me
under your wing and teaching me bookkeeping. I have been blessed because of it."
— Melissa Jarrel, former ABBA employee & subcontractor


Kate Stack found her true passion at age 10, the first time she played office. She uncovered another layer of her passion for numbers in her freshman year of high school in Mr. Smith’s algebra class. He reminded his students how integral math was to our existence. Kate uses math everyday in her life. She feels blessed to have had such a positive experience with numbers early on.

Kate joined the ABBA team in 1998 and found her life’s work. She believes that financial health, just like physical, emotional and spiritual health, is essential for one's total well-being. Kate enjoys helping clients achieve financial health by providing an accurate set of books and a proven audit trail.

When Kate is not busy with ABBA she loves spending time with family and friends. She was raised in Iowa along the banks of the Mississippi River where her family still owns a cottage. Some of her fondest memories are boating or waterskiing on the river on hot summer days, catching fireflies and playing family games of Euchre and ping-pong.


Chelsie Beiden has worked with the ABBA team since 2008, becoming a subcontractor in 2014. After her daughter was born, Chelsie desired the flexibility to stay at home with her baby girl. She received a degree in hospitality but soon realized she didn't feel passionate about this path. She discovered that her passion was geared toward numbers. Chelsie delights in cleaning up a “messy” set of books in order to make it functional. She has a heart for small businesses, especially construction companies. She believes that in order to succeed it’s essential to know what’s happening in your business. Chelsie enjoys being an integral part of the process by digging into the books and seeing what areas can use improvements in order to have a healthy business.

When Chelsie isn’t busy crunching numbers she is trying to keep up with her daughter, starting home renovation projects with her husband or booking a tropical vacation. She loves being outdoors and never turns down an opportunity to host a BBQ. Her family is the reason she wakes up every morning and works hard. Being a strong female, Chelsie strives to be an example for her daughter. She also wants her baby girl to learn to play even harder.


Sherri Brungart learned bookkeeping from Barbara Thornton. Sherri enjoyed it so much that she started subcontracting with ABBA in 2004, eventually handling ABBA procedurals and new client setup along with client bookkeeping.

In her personal organizing business, she also helps “keep Sonoma County organized” by combating office clutter, allowing clients to concentrate on the work they’re most interested in doing. Sherri grew up in the Woodland Hills in Southern California and came north to attend Sonoma State University. She then worked in San Francisco at a major advertising agency keeping seven offices on the same procedural systems. She’s lived in Petaluma on and off since 1979, and has enjoyed seeing the downtown’s transition. She never tires of the historic architecture and is a member of Heritage Homes of Petaluma. She also enjoys movies and trivia games, especially trivia games about movies.



If you are interested in joining our team of bookkeepers, please contact us
through this website and we’ll respond to you in a timely manner.