Yes, she still might be pregnant too. Most of the time there wont even be that little bit on the bottom of her stomach. It is Bacterial so the Brackish salt will help kill it off. I know it's this because she is still eating, and her stomach has caved in like that, plus the fact that her spine looks altered. Don't lose hope, she might survive. Is it likely? I wouldn't go that far... the odds are against her but fish have survived it in the past.
Make sure when you're dealing with this that you wash your hands and dont have the open wounds like I told you. This disease can infect humans if you aren't careful. If any other fish show these symptoms you need to move them too. But still, don't worry. If nobody else looks sick then they're probably fine, and the only way it can hurt you is if you basically drink the tank water or put an open cut in the tank.