 She was born in Dublin, where her father George Shanahan (1856–1944) was Assistant Secretary of the Irish Board of Works, 1895–1921 and Honorary Treasurer of the Statistical and Social Inquiry Society of Ireland, 1925–44.Her maternal grandfather was J. J. Clancy (1847–1928), Irish Nationalist MP for North County Dublin from 1885 to 1918.Via her maternal grandmother Margaret Hickie, she was related to the revolutionary, poet and author Piaras Béaslaí.