Her father Lawrence MacDermott was from Dublin and her mother Victoria Louisa Bradley was from Tralee, County Kerry.
While there in 1931, she gave an address on "Women in Irish life long ago" which Philip O'Leary described in 2004 as "unapologetically feminist".
For the Irish Texts Society, she edited Cath Maige Mucrama and produced a glossary and corrections for The Life of Aodh Ruadh Ó Domhnaill.
She got to know Cearbhall Ó Dálaigh at UCD, through the Literary and Historical Society, Conradh na Gaeilge and hillwalking club; in 1934, they were married.
[5] In 1983, five years after her husband's death, she was appointed to the Council of State by his successor, President Patrick Hillery.