Strong is the Ma'at of Re, Book 2: The Heirs

Tiye, the first wife of Ramesses III, has grown so used to being the mother of the Heir she can no longer bear to see that prized title pass to the son of a rival wife. Her eldest sons have died and the one left wants to step down and devote his life to the priesthood. Then the son of the king's sister/wife, also named Ramesses, will become Crown Prince and all Tiye's ambitions will lie in ruins.
Ramesses III struggles to enrich Egypt by seeking the wealth of the Land of Punt. He dispatches an expedition to the fabled southern land but years pass before the expedition returns. In the meantime, Tiye has a new hope: A last son she dotes on. Plague sweeps through Egypt, killing princes and princesses alike and lessening her options, and now Tiye must undergo the added indignity of having her daughter married off to the hated Crown Prince.
All Tiye's hopes are pinned on this last son of hers, but Ramesses III refuses to consider him as a potential successor, despite the Crown Prince's failing health. Unless Tiye can change the king's mind through charm or coercion, her sons will forever be excluded from the throne of Egypt.