Family tree▼
This source gives his mother: "Eve, v Gwrgan, king of Glamorgan, she was Iestyn's sister"
Here also Dwnn gives his mother: "Eva ♀ Gwrgan chwter Iestyn ab Gwrgan arglwydd Moranug". He also specifies that "Jane ♀ Brochwel ab Aeddan o Bowys" was another wife of his father.