Was it said, what was the cause of pancreatitis? Was she nourished through nasoduodenal tube in the hospital? She should avoid fatty and acidic food for a while and she has to drink enough - plain water or tea. With enough I mean the amount which will result in amount of morning urine she usually excretes.
You might want to call the doctor and ask for appropriate diet for her. I believe, if it is "only" soreness now, she should wait few days more and see, if it becomes better or worse.