The reason why she knows is because...(Dream sequence/future sequence now commences and we find ourselves at the wedding of Haid and B'rr)...
Vicar; "Does anybody know of any reason why these two should not be joined in Holy Matrimony?"
Cedric (aka Haids father

); " I Doooooooooooooooo (twit twoooo, hooooot) ooooooooo, Haiiiiids is a daughter of the Owl-kin and although this b'rr represents himself with an owl emotiooooooooooooon I have not had the chance to have a loooooooooong chat with him!"
Rob; "noooooooooooooo!"