i had a chick hatch that couldn't use it's lower leg and foot of one leg, but i refused to cull it. it gets along just fine hopping, and i figured if it showed distress, i'd cull it, but otherwise, i was giving it a chance. it can live here peacefully for as long as it wants. i grew up with a rooster that had only one leg due to frostbite, and it made it years and years. so she shoudl do just fine with one working leg.
bless you for trying to help her and give her a chance.
i hope she makes it.