Margaret Simon was born on September 13, 1847, in Rhode Island to Henry Simon and Catherine Roux. Her father was a jeweler who owned $6,400 of real estate by 1860. Her father served as a captain in the Union army, and he died on October 6, 1864. She grew up and attended school in Providence, Rhode Island, and by 1870, she was working as a dressmaker. She remained in her mother’s household until at least 1900, and she died sometime after 1900.