Mary opened a school at Newington Green in 1784 with her sister Eliza and a friend: there she made acquaintance of R. Price and other eminent Dissenters. In 1788 she wrote the first lesbian novel written by a woman, Mary, a Fiction.

It is the story of a woman who marries a man she does not love, and with whom she does not have sex. When he leaves on an extended voyage, her girlfriend Ann moves in. Mary may be autobiographical, for the author had a close and passionate relationship with a woman named Fanny Blood. Wollstonecraft herself was married.

Her book Vindication of the Rights of Women (1792) provided the philosophical underpinnings of the women's rights movements of later centuries.

In 1792 she went to Paris where she met Gilbert Imlay, and American writer, by whom in 1794 she had a daughter that she named Fanny. In 1797 she married W. Godwin, and she died of septicaemia shortly after the birth of her daughter, the future Mary Shelley.