In 1639, Donough's grandson, Conor O'Brien married Máire ní Mahon (MacMahon). She became one of the most famous women in Irish folklore who, due to her flaming red hair, was commonly known as "Máire Rúa" ("Red Mary"). She was born in 1615 or 1616. Her father was Sir Torlach Rúa MacMahon, Lord of Clonderlaw and her mother was Lady Mary O'Brien, daughter of the third Earl of Thomond. Her first husband, Daniel O'Neylan (also sometimes written O'Neillan or Neylan) of Dysert O'Dea Castle in north Clare died young and upon his death, she gained control of his substantial estate and a £1,000 fortune. This wealth enabled her and Conor to build a more comfortable mansion on to the tower house.