Depending on where it's broken, and how bad it is, you might try to splint it. You would have to keep her very quiet and confined for several weeks, and even then it might not work. I agree with old hen, a vet is best, or possibly a gentle passing.
I agree, a vet is always best, and euthanasia is an option too. If a vet is not an option and you want to try to fix it, let us know what bone it is and we will try to help you fix her. View attachment 1892703