I'm gluten intolerant (not quite as severe as celiac). You shouldn't have to worry about slight physical contact, like on your couch. (That's only an issue if the kids have an anaphalactic allergy--like nuts or shellfish--to wheat or corn.) If I end up touching something briefly, it's fine as long as I wash my hands afterwards or before I eat.
The most important thing is to clean (with soap and water) your food prep surfaces, containers, and implements so that any gluten is washed off before you prepare food for the kids, preventing "cross-contamination." If you have things with grooves or cracks (wooden spoons, older cutting boards, etc.) that have had bread / gluten on them regularly, you probably shouldn't use those to prepare food for the kids. Elizabeth Hasselbeck's book, G-Free Diet, has a chapter on how she makes her kitchen work at home (where she's celiac but her family isn't). If your local bookstore has it, it would probably reassure you a lot.
Kudos for you for being such a good friend. For those with food issues, having "safe food" away from home is such a treat.