Mary Ellen practiced as a civil litigator before being appointed to the County Court of British Columbia in December 1985. After the merger of the Superior Courts in July 1990, she presided as a justice of the Supreme Court of British Columbia until May 2012.  During her 26-year judicial career, Mary Ellen dealt with a full spectrum of civil litigation matters,including all manner of torts claims (personal injury, medical malpractice, solicitor’s negligence, municipal negligence), wills and estate actions, construction claims, insurance matters (disability, life, coverage), wrongful dismissal actions and other commercial disputes.

Following her retirement from the bench in 2012, Mary Ellen launched her mediation practice while Associate Counsel at Singleton Urquhart.  In early 2017 Mary Ellen joined her friends and colleagues, Barbara Cornish, and Simon Margolis, in forming Cornish Margolis Boyd Mediation & Arbitration, a firm which has quickly gained a premier reputation in the field of alternate dispute resolution.

Mary Ellen has been included in the 2020, 2021, 2022 and 2023 Best Lawyers in Canada for Alternative Dispute Resolution. She is a fellow of the International Academy of Mediators and the National Academy of Distinguished neutrals.  She has lectured on mediation for: Continuing Legal Education Society of British Columbia, Canadian Bar Association, Trial Lawyers Association of British Columbia, Law Society of British Columbia