Moulting usually is initially around the chest area.
Broken feathers on the back are often done by the cockeral.
She could be being pecked around the rear, if they have drawn blood they will keep doing it and that will certainly make her unhappy and listless, and she will try to keep away from them if this is the case. She will go downhill if they continue.
Can you put her into a hen ark where she can shelter, go inside at night and still be seen by the others during the day? This will give her time to herself if she is being pecked by others and give her a chance to recuperate.
Give her something tasty as a treat and see if she is eating ok (for example, a bit of tuna fish in it's oil, or some made up porridge oats).
Also, has she been wormed recently?
Hope she picks up, let us know how she does.
Best wishes.