I am so sorry for her. I am a Crohn's patient. I know that every patient is different regarding the foods that don't cause issues. I would suggest cooked vegetables. I like mashed potatoes, carrots, peas, green beans, and sweet potatoes. I like more, but those are all good cooked. They likely will need to cooked until somewhat soft, not crunchy. White rice is good and some kind of gravy over it might be nice. Fruits are better canned than fresh for me. I can eat fresh fruits at times, but usually peel them. The skins can be problematic for Crohn's. I also buy French bread from a local bakery without preservatives. I personally am fine with dairy, but others aren't. Some have a gluten or wheat issue. Think low-residue diet. There are lots of online sites with low-residue foods to choose from.
She will learn what works for her and if you have a good relationship, she will share this with you. I hesitate to tell people what I can and can't tolerate because I don't want to make everyone have to eat what I eat. I can usually find something to eat.
Snacks: I found that Luna bars have the protein I need and taste good. Rice Chex, Corn Chex, Cheerios are all good snacks, too. String cheese (if she can have dairy), boiled eggs, crackers. There are really quite a few choices and unless she is a very picky eater, she can find quite a bit to eat without feeling too deprived.
One really important thing is making sure she does not overdo. Resting might be very good for her. I hope you have a great weekend and she feels loved and supported.
Audrey