About Colleen Sinclair Prosser, Estate Planning Attorney

Colleen Sinclair Prosser concentrates her practice on estate planning law and heads the trust and estate administration department of The Sinclair Law Firm. She crafts plans for clients concerned about preserving their hard-earned dollars and providing for their loved ones in case of disability or death. Then, she makes certain that these plans are properly administered. Committed to educating the public about estate planning issues, she gives free public seminars on a regular basis. Ms. Prosser’s devotion to helping clients accumulate, preserve and distribute their wealth has met with much success. For seventeen years, Ms. Prosser handled a myriad of real estate transactions in the community. For the last six years, she has assisted clients with their legal needs in the Maryland/D.C. area.


Ms. Prosser began her legal practice as an associate at Nylen & Gilmore, P.A., in Calverton, Maryland where she practiced in the areas of real estate, and estate and trust administration and planning. She gained extensive experience as Commercial Counsel for the prestigious Chicago Title Insurance Company in Washington, D.C. before joining The Sinclair Law Firm. She is a member of both the Maryland and District of Columbia bars. She is admitted to practice before the United States Federal Court. Ms. Prosser is also a member of the Real Property Section, and the Estate and Trusts Section of the Maryland Bar. She has represented her firm as a member of the Prince George’s Association of Realtors, serving on the Legislative and Membership Committees, and the Maryland Land Title Association where she served on the Education Committee.


Ms. Prosser received her Bachelor of Science degree from the University of Maryland, College Park with Academic Honors. She earned a Juris Doctor degree at The Catholic University of America in 1990.


Colleen Sinclair Prosser carries on the tradition of excellence set forth by her family who are renowned for their business and civic contributions to the community. Her father, Ron Sinclair, is founder and principal of The Sinclair Law Firm and executive member of the American Academy of Estate Planning Attorneys. Her mother, Maureen Mershon, is a partner in Holiday Point Marina in Edgewater, Maryland. Both her parents and grandparents have given back to the community through numerous civic efforts. Ms. Prosser follows suit as a volunteer for the Hospice in Prince George’s County. Ms. Prosser is married to Les Prosser, Jr., an award-winning artist and son of long-time Bowie residents, Lester and Lucy Prosser. They have one son, Jake Prosser. Ms. Prosser and her family reside in Edgewater, Maryland.

Page Tools

  • Share this page SHARE
  • Print Friendly and PDF