Posting pictures may be helpful. If you suspect an ingrown feather cyst, you can disinfect the skin, and make a small incision or open it with a needle, and squeeze any pus out. Look for a feather inside it and remove it. You may want to start a new thread of your own for more attention.
Do you have crushed oyster shell available too? Just trim the extra fluff that is constantly getting soiled. If she is getting over molting, hopefully, those bare spots will fill in soon.
Can you examine closely for any moving lice or mites under her belly and vent? It looks like she is being feather picked, by others or herself. I would clean off the poop and urates, and trim any excess fluff where the poop is getting stuck. Watch how the others behave with her. They can suffer...