When Margaret Emily Trefethen was born in 1843, in Kittery, York, Maine, United States, her father, William Trefethen, was 48 and her mother, Sarah Brown, was 42. She married John Forsythe Hanscom on 26 April 1861, in Portsmouth, Rockingham, New Hampshire, United States. They were the parents of at least 4 sons and 2 daughters. She lived in Boston, Suffolk, Massachusetts, United States in 1880 and Philadelphia Monthly Meeting, Philadelphia, Pennsylvania, United States in 1910. She died in 1923, in Rockingham, New Hampshire, United States, at the age of 80.