Maud de Clere married Sir Roger de Lacy, Sheriff of Lancashire, Baron Halton, Constable of Chester & Baron of Pontefract, son of John de Lacy, Constable of Chester and Alice FitzRoger.
She is sister of the Treasurer of York Minster (name not known).
She is not Maud de Clare who married John de Braose, Lord Gower.
It has been assumed, without evidence, that she was the same person as Maud de Clare, daughter of Magna Carta surety Richard de Clare. If so, this would mean that she divorced her first husband Roger de Lacy (by whom she had at least one child around 1192) and then married William de Braose and had more children starting around 1196. As her granddaughter Matilda married a nephew of Maud de Clare, it seems impossible that these two women could be one and the same person.
MedLands. Makes her the daughter of Roger de Clare (d. 1173), not Richard the surety (whose daughter Maud has her own complications, and there's a Clere in there somewhere).
Coucher Book of Kirkstall Abbey, page CCCXXXV, printed ed WT Lancaster and W Paley Baildon, page 241. "Rogerus constabularius duxit in uxorem Matildem de Clere sororem thesaurarii Eboracensis Ecclesie". Another copy (Cottonian MS, printed in the Monasticon) says "de Claro", according to a footnote.