Rachel,
I am in a similar situation with my in-laws. We are going there the day after Thanksgiving. They are sincere in their efforts but really don't "get it". The last time my MIL made gf macaroni and cheese she used rice noodles but then said she got mixed up and added "only" a couple of teaspoons of wheat flour to the entire pan.
My son and I have a lot of delayed food allergies in addition to gluten so it will be a tough dinner for them to prepare. I can already see butter on the plain vegetables. I plan to coordinate with them and bring along a couple of dishes to share (although this is the day after I serve Thanksgiving dinner to my family).

--Judy