Poor thing. I'm sure you've tried to entice her with everything you can think of.Thank you Wyorp Rock, they haven't show any interest in her so she should be OK to go back with them. Her crop has not had anything in it for days. She may be drinking a little but I think she is just picking at food.
Do you have any Poultry Nutri-Drench or similar? I would try to direct dose her at 1cc per 3 pounds of weight. Try to get her drinking. The direct vitamins my give her a kick start, but I've found if they stop eating, are hunched up, tail dragging, then time is ending quickly.
I'm so sorry.