I'm thinking that if you just started with separate butter when your daughter got sick, you may still not be completely gluten-free. All containers of "stuff" like mayo, peanut butter, etc. have to be dedicated to the gluten-free eaters in the house. If you haven't already, go to the coping section here and read the Newbie 101 thread for more ideas.
How about kisses? If a gluten eater doesn't brush well before kissing you you can get glutened. And pet foods can be a problem. Not only do they (most of them) contain gluten that you will breathe in when you pour them into the dish, but your pet is now a source of glutening. Doggy kisses are just as dangerous as people kisses, and kittys may be even worse because they clean themselves with their gluteny tongues. Pet the cat and then pop something into your mouth without washing your hands first, and you are potentially glutening yourself.
As someone mentioned, medications and supplements should all be checked for gluten. Eating out is usually dangerous unless it is a totally gluten-free restaurant. And don't forget to read EVERY label, EVERY time you buy something. Formulas change depending on price and availability of ingredients. I have actually seen it when I buy two of something. It was an ice cream that I used to buy. One container from last week's shipment was as usual, but the second container was from a new shipment and it now contained guar gum. Now guar gum is not a gluten ingredient but it COULD have been. See what I mean?