This is a "Wild Mass Guess" entry, where we pull out all the sanity stops on theorizing. The regular entry on this topic is elsewhere. Please see this programme note.
Remember when Kate mentioned her fridge stayed cold during magic waves because of an expensive ice sprite egg? One day, Kate is going to look in the fridge for some apple pie and find that egg has hatched. Given Kate's luck, its first reaction isn't going to be "Mommy!"
As of Magic Bleeds, Kate doesn't own that refrigerator anymore.