She will surely get peritonitis, I would think. I don't have a lot of hope to offer you. Is there any way you can talk to a vet? That is really a terrible injury.
Is her crop actually exposed!? So the injury is to her actual crop rather than the skin? I would not put a chicken with such a horrific injury back with other chickens, they tend to pick at each other's bloody wounds, and that is the last thing this girl needs.
Honestly, I'd think seriously...