Best to break her since you're not going to hatch. Put her in a wire cage with food and water and keep her in there approx. 3 days or until she stops showing some of the broody signs (like puffing up, tik-tik-tik chirping, etc). At that time you can let her out and test if she goes back to the nest. If she goes back, put her back in the cage another 24 hrs, then test again.