Hector is the only child of Robert French, a Dublin solicitor. Her family claims to be descended from Irish gentry, the French family of Roscommon and Lord Annaly. On the paternal side, she is related to the poet Charles Wolfe and on her mother’s side, to the Shakespearian scholar, Edmund Malone. Her father loses his money in 1844 and moves first to Liverpool before settling in London.
Hector marries the explorer and archaeologist Alexander Hector in 1858 and together they have four children. She writes several novels during her early life, the first being Kate Vernon in 1854. However, her husband disapproves of her writing so she remains unpublished in his lifetime.
After Alexander Hector’s death in 1875, she uses his first name as her pseudonym and publishes over forty novels as “Mrs. Alexander,” many published by George and Richard Bentley. Among her books, all of which enjoy a wide popularity in the United States, are The Wooing O’t (1873), Ralph Wilton’s Weird (1875), Her Dearest Foe (1876), The Freres (1882), A Golden Autumn (1897), A Winning Hazard (1897), and Kitty Costello (1902).
Hector’s final novel, Kitty Costello, which presents an Irish girl’s introduction to English life and has autobiographic touches, is written when she is 77 years old and is barely completed at her death. A witty, clever talker, of quick sympathies and social instincts, Hector is in many ways abler and broader-minded than is shown in her writings. She dies in London, after suffering from neuritis for ten years, on July 10, 1902, and is buried in Kensal Green Cemetery.