Margaret "Peg" Mary Porter was born in Providence, Rhode Island in 1918. Her mother was a housewife, and her father was a janitor during the Great Depression. She attended Classical High School and obtained a scholarship to Pembroke College. She majored in Literature at Pembroke, and during her time there was the Chairman of the Sophomore Masque, Class President, President of the Question Club, and worked on the school newspaper, The Pembroke Record.
After her graduation in 1939, Porter began teaching in the Providence School system. She also taught typing, at night school, and was a home teacher for children who were too sick to attend school. In 1944, she married a WWII pilot and together they had six children. When Porter’s youngest child began kindergarten, she resumed teaching at Gorton Junior High School, where she taught until her retirement in 1986. Upon her retirement, Porter maintained involvement in teaching, working on a literacy program, volunteering for Meals on Wheels, and holding positions among her Pembroke Alumnae class.