Ann Cromartie was the daughter of a milkwoman and was taught to read by her brother. In 1774, she married John Yearsley, a yeoman worker and had six children. Despite living in extreme poverty, she managed to write poetry at night, using the pseudonym "Lactilla." Ann Yearsley came to the attention of Hannah More, who arranged for her collection of verse Poems on Several Occasion to be published in 1785 with a preface by Hannah. Several other collections followed, such as Poems on Various Subjects, and Other Pieces (1787), which contained an account of her quarrel with Hannah More over royalties; Stanzas of Woe (1790); and An Elegy on Marie Antoinette (1795). Ann Yearsley established a circulating library in Bristol and her play Earl Goodwin (1789) was performed in Bath and Bristol. She also wrote a historical novel about the so-called Man in the Iron Mask entitled The Royal Captives: a Fragment of Secret History (1795). Her final collection of poetry, The Rural Lyre, appeared in 1796. Ann Yearsley was one of many prominent Bristol women who campaigned against the slave trade. Her portrait was painted by Sarah Shiells and a mezzotint engraving of it is in the British Museum.