Have you tried apple cider vinegar (organic, with the mother) in her water? I use homeopathic remedies for my chickens. I would be giving her Cinchona officianalis (often called China) in her water in a 6c potency, and I'd put some of Silica 6x (some spell it Silicea) cell salt in her water as...
I am so sorry; you probably did this already. I wanted to let you know that there are homeopathic remedies that will help with the pain, and in other cases when you have them, the chicken could be allowed to die a natural death. Arnica or Ledum would help her feel better, most likely, and...