It sounds to me like she may be molting some, but that at least some of it is being lowest in the pecking order and being a little over crowded. Broken off feathers are definitely from the other girls grabbing at her.
If you can, get a helper and get her after dark off the roost. Your helper can hold a flash light and you can inspect her better. They are much more docile after dark! good luck!
If you can, get a helper and get her after dark off the roost. Your helper can hold a flash light and you can inspect her better. They are much more docile after dark! good luck!