For one, they run a “Scare B&B” (which is a way better business name than Hotel Transylvania) for monsters visiting Pennsylvania, and they know very little about American customs.
For a familial unit intent on keeping their identities as vampires secret, the Hauntleys are pretty awful at keeping a low, vamp-free profile.
Why Is The Hauntley Family So Awful At Hiding They Are Vampires?
Couldn’t they have given her an alias when she went to public school?