If she really is supposed to be Rebirth's equivalent of a 4th generation vampire then it's actually quite believable that she would not believe for a second that there was a vampire more powerful than her sleeping under some podunk American suburb. If the story was set in Iraq or Syria perhaps she would have approached things more cautiously.This is the reason i dont like Calisto death there, she would take things serioulsly now she know is possible to things older than her to be awake something she doubted as a complete joke and impossible