So do all vampires only eat kids in this world, or was this one just a weirdo?
Also, what are the chances that Lavie didn't actually die and instead was turned into a vampire herself? With her later dissociating and creating "Susie" as an alternate identity to deal with the drama of becoming a vampire? The super powers and stuff could just exist by virtue of her being an exceptionally powerful vampire.
The lie detector thing from the beginning probably could have been fooled if she actually, honestly believed that what she was saying was true.