I'm not sure her defence of "I was supplied real bullets instead of fake ones and didn't know the difference" shows her in a positive light for her technical abilities to be blunt. Of the three folks directly involved, I think she's the only one that stands some actual risk of jail time, so I'd hope her defence case is better than what is effectively a plea of "I don't know what I'm doing so its not my fault, its someone else's for supplying me real bullets in the first place".
Posted originally in mid Feb - I'd say 18 months looks to be about right, although she would have got much less with an initial guilty plea (like the producer did) because it was obvious that the chain of events started with her incompetence, and therefore she was always going to be found guilty once she admitted to loading the gun.