I would keep her separated from the others for a bit. Wet her feed with some water. If you don't mind investing money into her you could take her to a vet. When I had one with a broken beak it healed, but remained at a funny angle. If you want to give her some painkillers you can break a tablet in half and rub the two halves together to sprinkle the dust onto her mushy food. Aspirin can thin blood so don't use it if she is actively bleeding. If you can re-set it somehow that would be great, but if not she should be able to pull through just fine anyways.