If poop looks good and she still eats and more importantly, drinks, I'd chalk it up to the molt. I would not be surprised to see some lethargy and a pale, shrunken comb as well.
Have you tried wetting her feed to see if that makes it more appealing?
Or maybe get a small bag of non-medicated chick feed - higher protein, less calcium since she's not laying, and most hens seem to enjoy it. You can try wetting that down as well if she doesn't take to it dry.
Molting birds are uncomfortable and I do notice they eat less during the start of molt. I wouldn't worry about it as long as she's still eating and drinking some. Are the grass and worms things she's foraging, or is that stuff you're deliberately feeding her?