There's only a few things you can do since the damage is from mating. Separate out Mr. Rooster to give her a break and/or a saddle would be good too. The baldness on the head, that's not going to come back until molt, but if he's mating her a lot, then likely she will continue to be bald. Most feather loss on the back usually doesn't come back in until molt as well, ime. Feathers are broken/worn with an intact shaft.