It is probably related to her being broody for so long and not a part of the flock, plus her smaller size. Broody hens should be broken right away if they are not going to sit on eggs. When they sit for such a long period, they may become weak and malnourished.
I would leave her in the dog crate with food and water. Place her with the flock. If you can put a little log or roost in the crate, that might be good. I would get her comb healed, and then try reintroducing her very gradually with supervised visits. Since they will be able to interact but not hurt her, the crate may make it easier to reintegrate. But it might not work out. I have had to put a hen on the other side of the chicken fence and let her free range on her own. At night, I put her in her dog crate and let her out every morning to the other side of the fence. Eventually, she got back into the flock, but was on her own.