I really loved the fact that Lucy is not only the one who figures out what is happening before anybody else does, but challenges everybody else on why they are actually afraid of this. But it's never outright pointed out that there's no reason to be afraid of it, and even at the end when the wolves are shown running away from the house, the family brandishing their chair legs, it's still done in a creepy style, the wolves and people as silhouettes, with weird smoke in the sky and a dark house. The idea is great, the execution is great, it's just not for the fainthearted child.
Message
Just because something is traditional, that doesn't mean it's right. And don't be afraid of wolves in the walls.