Maud [mother of Geoffrey Fitz Peter (or Piers), wife of Piers de Lutegareshale], Lady of Costow, co. Wilts. [Ancestral Roots]
Maud de Mandeville [daughter of Geoffrey de Mandeville by Rohese de Vere]; married (1) Piers de Lutegareshale; married (2) Hugh de Boclande, living 1176. [Magna Charta Sureties]
Note: I have reversed the order of marriage which MCS has, because it certainly makes more sense according to the birthdates of the children. Both of Maud's husbands lived to be fairly old, making it very difficult, even doubtful, if she married both. I note that Ancestral Roots did not name her Maud de Mandeville (I think that the citation implies a prior marriage to someone from Costow, Wiltshire (possibly Hugh de Boclande?)), and that, according to Burke's Peerage, Geoffrey Fitz Piers did not use his mother's relationship to claim the Earldom of Essex. He used his wife, Beatrice de Say's descendancy from Beatrice de Mandeville sister of Geoffrey de Mandeville, 1st Earl of Essex. Thus, even though MCS clearly states her as Maud de Mandeville, daughter of Geoffrey de Mandeville, I have my doubts.