I don't think it's really fair of her to waltz in and say "no gluten today". That's way too short notice for such a huge change! Sure if she wants to go gluten free fine, but she's going to have to do all the work not you. At least that would be my approach. I went gluten free once ( I experimented a lot with diets to cure my acne) and it can get pretty expensive pretty quick. So if I were to go gluten free I would have to do it for everyone and raise my daily rate...it's a lot of trouble.