Born in Kowloon, China, on May 1, 1918, she was the daughter of Frank and Ethel Yaksol Mohler. Margaret attended Springfield College and studied teaching.
On December 18, 1942, she married Burt Charles Sheehan in Springfield, Mass. Together they had three children, Gary, Candy and Shari. Margaret was known by many names, Migs, Moppy, Mop-Mop and Mopster, and had many roles: wife, mother, friend, teacher, grandmother and great-grandmother. She was predeceased by her beloved husband, Burt, in 1981; as well as her brother, John.