X2 !!!! He's lonely. Just my own experience....geese will tolerate ducks and sometimes even show affection, but they do much better with another goose. I agree with what others have said, if you can get a mate for each of them.I think he's calling out for your daughter. He is imprinted on her and can hear her, so he's honking to let her know where he is. Geese do a lot of "here am I - where are you" communication so they won't get lost from one another and the flock. When he hears your daughter, he thinks she is calling out to find him, and he yells at the top of his lungs, not understanding why she can't find him.
My late goose would always honk when she heard a neighbor friend clear his throat (he does that really loud). She obviously thought he'd gotten lost. If he came over, she'd run to greet him.