[2] Born on 3 May 1849 to Michael Laffan and Ellen Saran Fitzgibbon in Dublin, Hartley was educated in the Dominican Convent of Sion Hill and Alexandra College.

She also began writing with articles such as 'Convent Boarding Schools for Young Ladies' submitted to Fraser's Magazine (June 1874).

[2] In 1880 Fannie Gallaher published her early novel Katty the flash: a mould of Dublin mud.

[6] Katty the Flash was successful and it was republished in the New York Sun who attributed their heavily amended story to Laffan.

[8] In 1882 she married Walter Noel Hartley who was a chemistry professor at King's College, London and Fellow of the Royal Society.