Sources differ as to whether Gwladus was Llywelyn's legitimate daughter by his wife Joan or an illegitimate daughter by Tangwystl Goch. Some sources[who?] say that Joan gave her lands to Gwladus, which suggests, but does not prove, the former. Gwladus is recorded in Brut y Tywysogion as having died at Windsor in 1251.
- She married firstly, Reginald de Braose, Lord of Brecon and Abergavenny in about 1215, but they are not known to have had a daughter Matilda de Braose. After Reginald's death in 1228 she was probably the sister recorded as accompanying Dafydd ap Llywelyn to London in 1229.
- She married secondly, Ralph de Mortimer of Wigmore about 1230. Ralph died in 1246, and their son, Roger de Mortimer, inherited the lordship.
- Roger Mortimer, 1st Baron Mortimer, in 1247, married Maud de Braose, by whom he had seven children.
- Hugh de Mortimer
- John de Mortimer
- Peter de Mortimer
- Ancestral Roots of Certain American Colonists Who Came to America Before 1700 by Frederick Lewis Weis; Lines 132-C-29, 176B-28
- John Edward Lloyd (1911) A history of Wales from the earliest times to the Edwardian conquest (Longmans, Green & Co.)