When Kawab died in his early thirties, Hordjedef was the next heir in line for the throne. In egyptian royal society, the eldest son and his descendants only assumed the throne thru direct inheritance. Hence, if your father died child, forget it. Your next eldest brother (regardless of whom his mother may be and despite possibly inferior blood) would inherit the throne before your sons did. Kawab and Hetepheres II seems to have managed one living daughter. She carried the direct blood and was heiress to the throne, after her mother. Hetepheres did not follow tradition but created havoc, marrying a prince that was not in line for the throne. Some point to a possible consipiracy, with Kawab being murdered and Redjedef forcing a marriage. Whatever the reason, her actions would lead to the disinheritance of all direct heirs, starting with herself, then her daughter, down to her brothers and finally, to their children. While Redjedef had three sons that were all named "king's eldest son", it is unknown if one of them was her's. As a second wife, the son who would've followed on the throne would come from the queen, Khentetenka.