I don’t think higher protein is related to ascites. Ascites is related to either heart failure, or liver failure associated with egg yolk peritonitis or internal laying. Feeding 16-20% is fine for chickens. Feeding excessive protein can be related to gout and kidney problems.
An enlarged...
I would keep her with her flock and just keep an eye on her. If she stays in a nest box for a long period again, then recheck for egg bound. Feel of the abdomen to feel if it is tight or spongy. I have had a couple of hens with enlarged lower bellies. It is good to keep track of them if they...