J.W.
Get her tested for food sensitivities, and concentrate on healing her gut.
Tests can include the IgE scratch tests, IgG blood testing, and even the IgA fecal tests.
Healing should include probiotics and pre-biotics and a diet low sugar and refined carbs (think about whole, fresh, non-processed foods).
Of all foods I'd try blindly eliminating, it would be gluten and dairy, but really, it could be anything, even something like eggs, or beans... which is why testing really is the best way to go.
Supplements that may help are fish oil, ginger, and boswellia.
See an MD specializing in integrative medicine.
Although this post is about dairy and the brain, it talks about various tests and the gut: http://itsnotmental.blogspot.com/2011/08/brain-health-cut...