Mary Wilkins moved with her family to Brattleboro, Vermont, in 1867. She lived at home after studying for a year in 1870–71 at Mount Holyoke Female Seminary (now Mount Holyoke College), read widely on her own, and began writing children's stories and verse. In 1883, by which time both her parents had died, she returned to her birthplace of Randolph, Massachusetts, to live with friends, and in that year she published in a Boston newspaper her first story for adults. She did her best work while living in Randolph in the 1880s and '90s. In 1902 Wilkins married Charles M. Freeman of Metuchen, New Jersey, where she lived until her death.

Narrated in a firm and objective manner with occasional subtle undertones of humour and irony, Freeman's stories were deft character studies of somehow exceptional people who, trapped by poverty or other handicaps in sterile, restrictive circumstances, react in various ways against their situations. Her use of New England village and countryside settings and dialects placed her stories in the local colour movement, and her work thereby enjoyed an added vogue; nevertheless, she avoided the sentimentality then current in popular literature. Although she produced a dozen volumes of short stories and as many novels, Freeman is remembered chiefly for the first two collections of stories, A Humble Romance and Other Stories (1887) and A New England Nun and Other Stories (1891), and the novel Pembroke (1894).