Do you have a rooster? Where is the rest of the flock?
You may want to catch her up and cage or pen her. Place her somewhere where she may feel safer.
This way she's got access to her own food/water and you can see what her droppings are looking like too.
Carefully inspect her all over for more wounds, for lice/mites, make sure her crop is emptying and feel her abdomen for any bloat/fluid.
I have to wonder if more is going on with her.
You may want to catch her up and cage or pen her. Place her somewhere where she may feel safer.
This way she's got access to her own food/water and you can see what her droppings are looking like too.
Carefully inspect her all over for more wounds, for lice/mites, make sure her crop is emptying and feel her abdomen for any bloat/fluid.
I have to wonder if more is going on with her.