Daughter of Sir Henry de Percy and Idoine Clifford. Grand daughter of Sir Henry de Percy and Eleanor de Arundel FitzAlan, Sir Robert Clifford and Maud de Clare.
Wife of Sir William de Aton, son and heir of Sir Gilbert de Aton, 1st Lord Aton. They married before Jan 1327 and had three daughters, Anastasia, Katherine and Elizabeth. Grandmother of Margaret Saint John Bromflete.