Cregan is the eldest son of Rickon Stark and with that heir to Winterfell, and he needs to marry to later carry one the line of his family, but cregan could never choose a woman until his father decided for him. The youngest daughter of the heir to the iron throne, Princess Rhaenyra. Her daughter just got 16 and is of marrigable age tho Cregan refused to marry her because he thought she was too naive and innocent, nothing for the north, his father forced him since he needed to marry soon.