At this moment, Lydia was naive. But she was mainly desperate when it came to learning her abilities. "I'm willing to do whatever it takes." Which was the truth. She was to the point where she was desperate to learn how to handle her screams and be useful to her friends. Both new and old. And if Mal was the one to teach her, than be it.
"Do any of these spells work..I mean, the whole concept of magic that is." She had to ask, as she seen Mal was going through great lengths to get this store to perfection before opening it to the public.