Margaret de Venoix, Heiress of the Office of le Mareschal - Pembroke castle

According to Diana Jean Muir, she was born November 5, 1083, in Venoix, Calvados, Normandy, France (where her father was from). Died 1119 in Pembroke, Pembrokeshire, Wales. She was evidently his only heir, and married Gilbert FitzRobert Giffard, le Mareschal (sui uxoris) in 1104, in Pembroke.

She also states that her husband was born 1075 in Somersetshire, England; died 1130 in Marlbourough, Wilshire, England.

https://books.google.com/books?id=mZViDwAAQBAJ&pg=PA242&lpg...

Ancestors of Clifford Earl McAllister Vol 2 Family Groups
By Diana Jean Muir is wrong she never existed.

GILBERT "the Marshal", son of --- (-1130 or before). Master Marshal of the king's household under King Henry I[1267].

m ---. The name of Gilbert’s wife is not known. It is possible that she was the heiress of William FitzAuger: the Testa de Nevill includes a writ of King John dated 1212 which records that, after the conquest, King William I granted "manerium de Boseham" in Surrey to "Willelmo filio Augeri", and that later "Willelmus Marescallus" (presumably identified as the future first Earl of Pembroke, see below) held the manor "[jure] hereditario"[1268].

http://fmg.ac/Projects/MedLands/ENGLISH%20NOBILITY%20MEDIEVAL1.htm#...