Frances Power Cobbe was born on December 4th 1822 at her family's estate at Newbridge House in North Dublin. Her family were strongly evangelical in their faith but Frances began to question conventional religious belief and after her mother's death in 1847 she stopped attending church services. In 1855 she published Essay on Intuitive Morals setting out her own belief on religion and ethics. This caused a rift with her father and she left home permanently soon after. Frances travelled extensively in the years that followed and published Italics (1864) about her travels in Italy. She became involved with the Ragged Schools movement in Bristol and her time working with poor, sick and unemployed women fueled her interest in women's rights. She wrote a number of pamphlets and essays on women's education and women's suffrage, campaigning for assault to be grounds for separation. She was a leading member of the National Society for Women's Suffrage. In the 1870s she focused mostly on her campaigns against vivisection and was a founding member of both the National Anti-Vivisection Society and the British Union for the Abolition of Vivisection.
A regular contributor to a number of magazines and periodicals she also wrote an autobiography published in 1894. Frances lived with her lifelong partner the sculptor Mary Lloyd from 1860 until Lloyd's death in 1896. They are buried together at Llanlltyd in Wales were they lived most of their lives.