Fernande R.V. Duffly earned a B.A. from the University of Connecticut in 1973 and a J.D. from Harvard Law School in 1978. She then joined the litigation department of the Boston law firm then known as Warner and Stackpole. As an attorney, she provided pro bono legal services to indigent clients through the Volunteer Lawyers Project. Justice Duffly is a member and past president of the board of the National Association of Women Judges. She has served on the Boston Bar Association's committees on pro se litigation and attorney volunteerism, the Probate and Family Court's committee on pro se access to the courts, the American Bar Association's subcommittee on the representation of children, and the Supreme Judicial Court's Standing Committee on substance abuse. In 2001, Justice Duffly was part of a delegation of Massachusetts judges invited to China by the Supreme People's Court, where she promoted the rule of law. She has also presented educational programs to visiting Chinese judges.
Justice Duffly has received the Distinguished Service Award from the Probate Judges Association, the Distinguished Jurist Award from the Massachusetts Association of Women Lawyers, and the Trailblazer Award from the National Asian Pacific American Bar Association. She has also been recognized as a Diversity Hero by Massachusetts Lawyers Weekly.
In 1992, Justice Duffly was appointed by Governor William Weld to the Probate and Family Court, where she served until her appointment to the Appeals Court in 2000 by Governor Paul Cellucci. In 2011, Justice Duffly was appointed by Governor Deval Patrick as an associate justice of the Supreme Judicial Court.