Yeat was born as Gráinne Ní hEigeartaigh in Dublin and raised bilingually in Irish and English.
As well as obtaining a degree in history from Trinity College Dublin, she studied piano, voice and harp at the Royal Irish Academy of Music in Dublin and also traditional songs and music from the Irish-speaking (Gaeltacht) areas of Ireland.
[2] She wrote and researched the history and music of the Cláirseach (wire-strung harp), and she was one of the first professional musicians to revive and record this ancient traditional instrument.
She wrote entries about Turlough O'Carolan and other Irish harpers in the New Grove Dictionary of Music and Musicians.
They had three daughters and a son,[3] Caitriona, Siobhán, Síle, and Pádraig.