Staff Bios

Sima Cheregosha – Founder & Board Chair

Sima moved to the Dallas area twenty five years ago, and co-founded ArborCreek Montessori School (ACMS) in Farmers Branch, TX, now completing two decades as an educational institution par excellence. Sima’s accomplished career as a seasoned Montessori educator, first as primary guide, then Director, and now as Head of School, has uniquely positioned her to launch ArborCreek Montessori Academy (ACMA) for age groups 9-18. She believes Montessori education develops motivation and discipline; it empowers students with a sense of self worth and confidence in a rapidly changing world.

As founder and chairperson, Sima provides the vision and strategy to make ACMA a reality. She directs board members in their efforts and motivates a highly efficient team. Her leadership qualities make her the driving force behind ACMA.

“I am inspired by people who will stop at nothing to have a positive impact on other people’s lives. I feel extremely fortunate to be part of such a committed team engaged in creating an environment for older students who will undoubtedly benefit from the value of a Montessori education.”

Sima is an American Montessori Society (AMS) Life Member, AMS certified for ages 3 to 6, AMS trained for ages 0-3, and Language and Math trained for lower elementary. She holds a Master of Liberal Studies from Southern Methodist University, preceded by many years experience in literature and foreign language studies. She is fluent in English and Persian.

Kelsey O’Keefe – Board Member

Kelsey is a parent of two ACMS students and a partner in a Dallas law firm where she practices immigration law. A native of Seattle, Washington, Kelsey and her family moved to Dallas in 2014. When her children started school at ACMS, she quickly saw the positive change and meaningful growth in them, and she wanted to learn more about Montessori education.

As a ACMA board member, Kelsey works on fundraising projects and operational planning, which provides her the opportunity to learn more about the many wonderful organizations in our area that support a greater future for the children in North Texas. Kelsey is a self-starter and brings outstanding value to the board – her perseverance, single-minded focus, attention to detail and consistency are invaluable.

“I am thrilled to be a part of the future of ACMA, where children will continue the journey of realizing their full potential as citizens of our community. Together we are ensuring that each child will be the kind of thoughtful, kind, and driven individual that makes the world a better place. It is an honor to be part of this project.”

Kelsey is a member of the Washington State Bar Association and the American Immigration Lawyers Association.

Andrew Quintanilla – Board Member

Andrew’s passion for his children’s education brought his family to ACMS. He has observed that there are plenty of professionals and students who remain unfulfilled with their work and education. Andrew believes the ‘one-size-fits all’ approach followed in the current school system often hinders individuals from discovering their passion and calling. He is convinced that the Montessori method fosters an environment that allows children to appreciate learning and helps them find their purpose in the world.

Andrew’s desire to change the way people work encouraged him to join the ACMA board, where he conducts comprehensive research and data compilation for market analysis, feasibility, and demographics. He also engages in identifying grant opportunities and applying for grants. Andrew is a solid asset to the ACMA board with his steady commitment, composed demeanor and sound work ethic.

Andrew is a Certified Food Scientist with a B.S. degree in Food Science and Technology from Texas A&M.

Berenice San Juan – Board Member

Berenice is a parent of two ACMS students. She was excited and motivated to be a part of ACMA because she strongly believes that her children would benefit long term if there was opportunity for them to extend their Montessori education beyond the primary grade level.

As a board member, Berenice provides expertise and guidance in financial and accounting matters as well as crucial administrative support on many projects. Her dedication and eagerness to find solutions rounds out the ACMA board.

Berenice is fluent in English and Spanish. She has a degree in Accounting and is a small business owner in Dallas.

Jennifer Wester – Executive Director

Jennifer is a parent of two ACMS students and lives in the Dallas area with her family. She has had an illustrious career as a professional skater in ice dance, having represented Team USA from 2005-2010. She has performed for live audiences and TV in several countries, and credits skating with enriching her life with inter-cultural experiences and friendships she otherwise may never have experienced. Since 2008, as an athlete representative on advisory committees, she participated in the governance organization of United States Figure Skating. From 2010-2015 she also directed and owned a community skate school in Newington, CT.

“I’m extremely thankful to have found ACMS for my children, and excited to be the executive director of ACMA working closely with the board.. I believe academia must not produce a normalized product because no child deserves to be averaged. Montessori is a proven, successful response to the need for ever better and individualized education while simultaneously teaching children how to create and interact within community and respect differences; it’s everything that public education doesn’t provide.”.

Jennifer holds a degree in computer science and fine art from Yale University, and is fluent in English, Russian, and Italian. She is co-owner of a family business supplying custom pressure vessels to aerospace and research facilities and is active as a metal sculptor and painting artist.