Connor (unofficial)

King's Quest II: Romancing the Stones
In KQ2+ due to a curse put on Graham by Morgeilen he is left with no residing heir, as his son and daughter made forged their own paths in other kingdoms. Fortunately, the new champion Connor had arose in Daventry and was worthy of filling in the void. When had returned to Daventry king Graham discussed the idea of making him heir, and wondered if he would be able to fulfill his obligations as Champion Eternal and still be able to rule Daventry. Since he had proven his nobility by defeating Lucreto and saving the world, King Graham decided to make him his First Knight. Thus he became his successor and heir to throne.

It should be noted however, that in the official King's Quest Companion it is implied that Rosella only visits Etheria and she along with Edgar would remain the future heirs of Daventry.