She was appointed lecturer in palaeobotany at Manchester University in 1904 and then taught at Imperial College in London. It was, however, her books, particularly Married Love (1918) and Wise Parenthood (1918), with her clear views on birth control, that made her famous. With her second husband, H. Verdon-Roe (1878–1949), she founded a clinic for birth control in London in 1921. Her activities roused opposition but also steadily increasing support among the medical profession and the general public.