Having done the GAPS diet for several months, I do think that there may be some misunderstanding as to the purpose and/or application of the diet. And while simply following the GAPS diet in and of itself is not automatically gluten free (vinegar for example may or may not be gluten free) it can easily be made gluten free.
All of that said, what symptoms are appearing that cause her to feel she is getting glutened? And if she works outside the home, could it be happening at work? I have to be very careful preparing and eating my lunch at work as I've had co-workers accidentally fling crumbs across the table into my food, or one time I saw someone pass their freshly toasted bread slice over my coffee cup which I was getting ready to fill up.