Mary Kierstead passed away peacefully on September 26, 2026. She was born in Malden on September 27, 1951, the beloved daughter of Harold and Elizabeth (Campea) Kierstead. A proud graduate of Malden High School Class of 1969 and Tufts University Class of 1973, Mary earned a Master's in Mathematics from Tufts and a Master's in Computer Science from Rutgers.

Mary enjoyed a varied career, initially working as a programmer on a medical research project. She later found her calling in teaching, starting at Northeastern University, and continuing as a math teacher at Arlington and Andover High Schools. As an advisor to the math and computer science teams, she formed strong bonds with her students.

Her love for dogs was evident in her care for her golden retrievers: Augie, Isaac, and Sherlock.

Mary was the cherished wife of Michael Weiss for 42 years and a devoted mother to Gregory Weiss Kierstead and mother-in-law to Elizabeth McCullough. She is survived by her sister Marjorie Godding, brother-in-law Paul, and nephew Michael. Her presence will be missed by her many lifelong friends, with whom she shared a deep connection.

An active community member, Mary was involved with the Malden Library Crew for many years. In retirement, she enjoyed exercise at the Y, gardening, mahjong, and book club with her oldest friends. She embraced her love of math and baking on Pi Day, loved visiting the Berkshires for its cultural offerings, and enjoyed traveling.

Visitation will be at the A. J. Spadafora Funeral Home, 865 Main Street, Malden on Tuesday, October 6, from 11:00am-1:00pm, followed by a gathering at Anthony’s Restaurant in Malden.

Donations in Mary's memory may be made to the MSPCA, Breast Cancer Organizations, and the American Lung Association.