Could you get her into a pan of warm soapy water and wash her off, then take a new picture? I can’t see the vent if there is a prolapse. First make sure the vent or cloaca is not prolapsed.If the vent is pooched out she might have an egg in there or be constipated. Then I would take a disposable glove and lubricate her vent with vaseline or olive oil and feel inside her vent for any crusts or hard poop, or possibly an egg or lash egg. If she is egg bound, she needs 300-500 mg of human calcium with vitamin D or a Tums split into and given orally. If she is prolapsed, try to push her cloaca back inside and oil it inside and out. If there is thick poop or crusted urates inside and around the vent, I would try to remove any that you can, and apply oil in the vent opening. Yes, nursing chicken is fun, isn’t it? If she has vent gleet, her vent and droppings will smell worse than normal, and her white urates may leak constantly from her vent. The skin make look irritated and she may have feather loss around the vent. Has she been drinking and eating?