My oldest "should" be gluten free. She resists the idea with a strong attitude. How we have handled it is all family meals are gluten free. The end. I do not buy things to make multipl meals for dinner. Most meals are naturally gluten free but if we make pasta it's Gf pasta. Her lunches are gluten free because I just don't really buy bread Gf or otherwise. It was getting moldy because 3/5 of us were not eating it.
If we go out or she is with friends sh will eat wheat and on ocassion she will spend her own money on Nilla wafers and goldfish but at home the opportunity to have gluten is minimized.
This has meant that a majority of the time she feels good. Her skin is clearer and her belly feels and looks better. Then she "cheats" and the symptoms are me obvious because she doesn't have regular exposure.
At the end of the day it's up to her but since I do the shopping I get a say because it effects our budget and whole house health.