CarrieLee, you may want to look into some alternative methods like chinese medicine or homeopathy. There are some Chinese herbs that can make a body less sensitive to allergens, and homeopathy is very individualized and also addresses these sorts of things.
I am personally very skeptical that the methods on this site can fix actual food allergies. Food intolerances, yes. But I can’t think of an example of someone who has come here and eliminated their peanut allergy, for example. Allergies are more autoimmune in nature, and true allergies usually get more severe over time every time you have an exposure.
I’m sure a good probiotic could help with stomach issues, but usually you have to totally avoid the offending foods to get healing. I know a decent amount about food allergies have a couple of very severe ones myself (life threatening). I don’t think GAPs or anything else would address them because I have issues from breathing in particles in the air or touching the offending foods.
If she avoids the foods and heals a bit, maybe she can introduce the mild allergens later. Kids also are more likely to outgrow things than adults, but usually that also involves avoiding the problematic foods for awhile.