Born in the town of Hampden, Maine, she grew up in Worcester, Massachusetts among her parents' relatives. She was the first child of three born to Joseph Dix and Mary Bigelow, who had deep ancestral roots in Massachusetts Bay Colony. Her father was an itinerant bookseller and Methodist preacher. [a] At the age of twelve, she sought refuge with her wealthy grandmother, Dorothea Lynde (wife of Dr. Elijah Dix) in Boston to get away from her alcoholic parents and abusive father. In about 1821 Dix opened a school in Boston, which was patronized by well-to-do families. Soon afterward she also began teaching poor and neglected children out of the barn of her grandmother's house, but she suffered poor health. It has been suggested that Dorothea suffered from major depressive episodes, which contributed to her poor health. From 1824 to 1830, she wrote mainly devotional books and stories for children. Her Conversations on Common Things (1824) reached its sixtieth edition by 1869. Her book The Garland of Flora (1829) was, along with Elizabeth Wirt's Flora's Dictionary, one of the first two dictionaries of flowers published in the United States. Other books of Dix's include Private Hours, Alice and Ruth, and Prisons and Prison Discipline.