Please remind me. Is she getting probiotics? How about vitamins? Sometimes a recovering chicken will still act sick because they're weak from their ordeal, having lost weight, and not regained their appetite.
Along with probiotics, try a straight shot of Poultry Nutri-drench mixed into some sugar water. You can stir in a little raw egg, as well, for a real protein boost. The result can often be dramatic.
My sick pullet was improving, and yesterday she regressed and she couldn't stand. This morning, I mixed up a solution of the aforementioned ingredients, and I tubed it into her crop. I left for town shopping and returned four hours later. She's now standing and moving around, and her appetite has improved.