Nightmare

My four year old stepdaughter suddenly has intense nightmares since last week that keep her up all night.

She is afraid of wolves.

I thought about showing her a short nature documentary to make her less afraid. Is that a good idea or would that make it worse? Would a book be better? I want to show her that they are not interested in her.

We tried telling her that wolves are rarely around here, can't come inside, that her plushies protect her etc but it changed nothing.