If they can test her poop for worms and coccidia as well as treat her today, that would be good. Nystatin is a good drug for sour crop. Her sour crop symptoms can be secondary to a reproductive disorder or other conditions. Once I start seeing crop problems with one with suspected reproductive problems, they don’t seem to get better. I treated one hen with crop problems for 6 weeks last year, and her crop just never seemed to function normally. Doing a necropsy if they die, will sometimes give answers as to what the problem was.