Leave her for a day or two to see if she'll come out of it herself. If she doesn't, you have a few options for trying to break her.
The first is dunking her in a bucket of water. Just do it a couple times a day, quickly, and see if that does the trick. Also try putting ice cubes under her...
7 hours isn't long enough to determine she is broody. Once you know if she is broody for sure, then you can go about breaking her. There are a few different ways to do this.
Is she clucking like mad when removed from the nest, looking like a huge cotton ball with her wings out? If it is just...