Predators sometimes attack the crop. I would pull back feathers or trim if necessary to fully examine the crop for wounds or punctures. Chlorhexidene 2% is very good to wash wounds, and Hibiclens diluted with water half and half works too. Plain antibiotic ointment can be put on wounds twice a day when dry. If a vet is possible, that would be best. Can you tell if any water or liquid is coming out of the chest where the crop is located? How does the crop feel—full and hard, doughy, or puffy? Check it again in the morning when she wakes to see if it has emptied overnight. If a hole or wound is found, the crop and skin can be separately closed with sutures or super glue.