I'd definitely try some egg or chick-crumb if she won't take pellets. I agree that you should perform a second float-test (you can do this at home, too) to ensure the worms have been taken care of, and re-medicate with a different medication if necessary. As
@Wyorp Rock suggests, introducing some oil; coconut (or olive works too, though solid-form oil is easier to introduce into the crop) and gently massaging her crop may help; it could be that the feed is becoming impacted as she is having a lot of fibrous foods.