Mary Hetherington led the way for women in the legal profession. She was one of the first female litigators in Alberta, opening her own law firm and acting as counsel in several high-profile criminal cases. Known for her tenacity and intelligence, she served as a judge of Alberta's District Court, and was the first woman appointed to the Court of Appeal of Alberta. She also played an important role in the courts in the north, where she sat as a deputy judge in the Northwest Territories, Nunavut and Yukon.