Continuity mistake: When Chelsea drinks all the punch, you can see that her face is soaked. The next shot you see of her, her face and hair are dry.
Continuity mistake: When Cory is talking to his dad about not trick or treating with him, look at his barbell. The number "one" written on it keeps appearing and disappearing between shots.
Visible crew/equipment: When Cory is telling his dad that he doesn't want to trick or treat with him anymore, you can see studio lights in the head mirror that Mr. Baxter is wearing around his head.
Answer: Psychic ability run in Raven's family, while the abilities skipped a generation with her mother, her Grandmother Viv was also a psychic.
OneHappyHusky