William the Conqueror already had fathered seven children by the time he fough at Hastings: Robert Curthose (1054-1131), Richard (1055-1081), Adeliza/Alice (1055-1065), Cecilia/Cecily (1056-1126), William Rufus (1056-1100), Agatha (1064-1079) and Constance (1066-1090). Odo would have no right to the Duchy of Normandy though he could take the Regency for his nephew Robert (who would only be 12).
It also seems to me that Harold Godwinson also had children on his side... But I sadly don't have the details nor their names.