Droppings look pretty normal, I see nothing remarkable. There are feathers, I'm not sure that she's not actually starting molt....Is anyone else molting now? I see feathers and feather shaft dust/particles in/around the droppings, so someone appears to be, and the feathers in the picture are white... Sometimes molt is so soft and gradual that it can be missed if not really looking for it. I'm not saying that you are wrong, when we feel something is off, we are usually right. I just don't see anything obvious that helps home in on why she may not be feeling 100%. And sometimes molt really affects them a lot, even if it hasn't before. I have several molting right now, they are standoffish, tend to lay by themselves away from others, and don't always eat well.
You can try giving some poultry nutri drench for a few days, it's faster absorbed and gives them a boost, and may help with appetite. Don't use for more than a few days running, once a day, too much can cause diarrhea. Try giving her some scrambled egg, see if she can be enticed to eat that. There are also recipes on line for things like 'molt loaf', a higher protein treat you can try. I would try to stick with things that are good protein sources. And continue to monitor the crop. You can also make a mash with the feed, just mix with some water, experiment with consistency, some like it thicker, some like it runnier. They usually like it that way.
