Need Help

I recently received a chicken who's past is unknown. She is having many cosmetic problems (she eats, drinks, and lays well enough) and I'm at a loss as to what to do for her. I live in New Hampshire so our winters can be tough so I'm trying to get her as good as I can before the worst of the weather gets here.
She has missing toes-I assume from frostbite, big lumps on the bottoms of both feet, she is obese (weighs 10lbs), doesn't have many feathers on her stomach/ bum, the feathers on the tips of her wings are gone and there is bone showing which was bloody today, her leg scales are "up" maybe from a case of mites -I'm not sure. I just really need some help with this poor girl. She's a sweetheart and she's part of the family.
I can send pictures if anyone needs them or thinks they can help!!
Thank you!!