The Annals of Ulster record the death in 1080 of "Derbhforgaill daughter of Brian´s son, wife of Diarmait son of Mael na mBó…in Imlech”. 1
Marriage Information:
Derbogaill married Diarmait mac Máel na Mbó, rí Laigin, rí Laigin, son of Máel na mBó Uí Cheinnselaigh. (Diarmait mac Máel na Mbó died on 7 Feb 1072 at the Battle of Odba, Leinster, Ireland.)
Sources
1 Foundation for Medieval Genealogy, Medlands: Derbogaill.