OK, then here's how you tell for sure it's the crop. Put a little blue food coloring in her water and then offer it to her to drink. If the fluid coming out is blue, you know this is her crop.
In the mean time, we really need to address the cleaning of the wound. It's a bit late for hydrogen peroxide, but the wound needs to be dressed. Because the wound may be going into the crop, you really can't use hydrogen peroxide or iodine as they may get into the digestive system. Instead, use clean saline and again thoroughly clean the wound. then you'll want to dress it with neosporin.
If you determine that the wound is in the crop, then you can get a set of sterilized suture material with attached needle at the feedstore often enough. Call around and see who has it. You'll get the size for dogs and cats if they ask. The needle is curved which makes it easier to put into the skin and have it come back out. Because the suture material is sterile already, you don't have to worry about it infecting the wound further.
If this is NOT the crop, do not close the wound. Closed wounds fester and breed bad bacteria (which hate oxygen).
It's not an easy decision, but hopefully this will help. Good luck!