By 1906 after being widowed seven years previously, her mother moved the family to Dublin, where they lived at 66 Botanic Road, Glasnevin.
[4] She taught French at a number of schools in Wales between 1919 and 1946, publishing an edition of the Irish tale Tóruigheacht Gruaidhe Griansholus ("The Pursuit of Gruaidh Ghriansholus") in 1922, and Ireland and Wales, their historical and literary relations in 1924.
[4] During this time she published an edition of Eachtra Uilliam, an Irish version of the werewolf legend of Guillaume de Palerme, in 1949, Five Seventeenth Century Political Poems in 1952, Trompa na bhFlaitheas, an 18th-century Irish translation by Tadhg Ó Conaill of La trompette du Ciel by Antoine Yvan, in 1955; The Stowe Version of Táin Bó Cúailnge in 1961; and Cath Finntrágha in 1962.
She never married, but lived with her companion Myfanwy Williams at 17 Raglan Road in Ballsbridge, after moving to Dublin in 1951.
[4] She was sister to Alfred O'Rahilly, a noted academic, President of University College Cork and Teachta Dála (TD) for Cork City, and Thomas Francis O'Rahilly an Irish scholar of the Celtic languages.