Maybe being an inmate is the best punishment for her, then. Make her learn empathy for the other side.

It sounds like she's not generally violent, but she reached a point where she saw only the worst in everything and everybody, including herself. And no one likes to think that someone's looking at you and seeing only the terrible. Even if she doesn't hurt anyone again, everyone knows that some part of her thinks we all deserve it.

Who were in the engine room at the time?