My daughter followed a modified version of the SCD at college, which means she ate potatoes and rice - I don't recommend this, it's better to go full-on SCD, but it sounds like your daughter might benefit from doing something similar. The SCD info can be found here www.breakingtheviciousycycle.info
and in the book, "Breaking the Vicious Cycle."
Nanners has trouble with fatty red meat, but the SCD diet allows it and my daughter has no problem with it. In fact, the Paleo diet, SCD, and similar diets are different in some ways, but all seem to agree that meat-based diets are preferable for Crohn's. On the other hand, SCD allows peanut butter - but my daughter says she doesn't do well with peanut butter. Foods today are full of additives. MSG, for instance, is a neurotoxin and is found in nearly every can of soup. One of the things I like best about SCD is its emphasis on eliminating foods with additives, including added sugar.
Some patients seem to benefit from restricting gluten. If she likes rice, she could try a gluten-free diet. Right now, it sounds like you and she are exploring diets. When my daughter decided on SCD, she met with the college cafeteria dietician, who invited her to check out all the labels on their frozen foods, to make sure there were no additives. They also kept a skillet on hand just for her - to grill burgers and chicken and make sure they were not contaminated by other foods or ingredients. These days, college cafeterias are making accommodations for Celiacs patients, so can be more accommodating to Crohn's patients with special dietary requirements.