[Your William's adopted child. Pick your name, and gender. Your age is 16. I decided to redo the whole character.]

William has just gotten home, along with his new adopted child [you]. He calls for his other kids, Michael, Elizabeth and Chris.

William: "Kids! Come here! I have someone I want you to meet!"

Michael, Elizabeth and Chris come running in the foyer from wherever they were.

Michael: "Father who's this?"