Lynn - in your case, you're probably better off eating GMOs than non-GMO - every GMO crop is tested extensively for all known allergen causing proteins. Conventionally bred crops are not tested at all - so it's possible for new varieties to introduce proteins that survive the gut and cause...
This sounds like Gluten isn't actually the problem - have you verified that shes not allergic to one of these grains specifically? She could be celiac and also be allergic to wheat.