Robert II FitzHugh de Grandmesnil - RE Medlands: No Children with Agnes de Meschines?

It's plausible that daughter Agnes was named after a mother by the same name, but it's not evidence assured.

Robert de Grantmesnil & his [first/second] wife had [two] children:
b) AGNES de Grantmesnil (-after 1115). Orderic Vitalis records that Robert had recently married "Agnete filia Rodberti de Gretemaisnilio" when he was banished from Normandy by Henry I King of England, and left with her for Apulia[367]. The chronology suggests that she was born either from her father’s first or second marriage. m ([1115]) ROBERT Seigneur de Moulins-la-Marche, son of GUILLAUME Seigneur de Moulins-la-Marche & his first wife Albreda [de Moulins].

Robert II FitzHugh de Grandmesnil is your 28th great grandfather.