What to do?

If you are invited here and there and can't possibly eat the breads/cookies/cakes being offered, what do you say or do?

Do you get support from family/friends about gluten free or do they try to push "oh just a little won't hurt you?"

This will be the first year for my dd, but I feel I prepared the family years ago when I: brought my OWN water, had organic veggies in purse and/or or just plain didn't eat at all.