She married her first husband, John Taylor, in 1826 at age 18. Together, they had three children: Herbert, Algernon, and Helen Taylor. In 1831 Harriet met John Stuart Mill. How they met is the subject of some speculation, but some suggest it was planned by the leader of Harriet's Unitarian Congregation. John Taylor invited Mill to dinner because of his wife's mutual interest in women's rights. Taylor was already not only writing poetry, but was interested in social reform, and had written a lengthy "Life of William Caxton" (which is more of a comprehensive history of the printed and written word) for the Society for the Diffusion of Useful Knowledge. Around the time she met Mill, she was, or began, also writing a series of unpublished pieces on women's rights, ethics, toleration and marriage.