Do you want her to incubate eggs or do you want her to stop brooding & start laying again? I'm guessing that you have other laying hens, and they must have been getting into the nest and adding their eggs under your broody. Once a hen decides to brood, she very rarely lays any more eggs herself. She plans to start incubating her clutch all together, any additional eggs she would lay would not be ready to hatch when the first ones did.
The best way to break a broody is to put her in a wire-bottomed cage, like a rabbit or parrot cage, set or hang it high so there's a nice air-flow coming up from the bottom. Supply food & water but NO bedding. After 3-4 days she should be ready to resume her previous lifestyle.
