I just want to say that i know you are new to this CF world and it is incredibly new and scary. I was there -- and it sucks. I know you are overwhelmed and afraid. The thing is that as much as we would like, we can't wrap our CFers in a bubble and keep them from any germs. Do the best you can. CFers get colds, normal colds, just like everyone else. Sometimes it will mean that the bugs in their lungs will get kicked up a bit and the cold will turn into the need for antibiotics from your CF center. But it is also possible that they will get a cold and it will go away just like it does for other kids. I'm not saying to slobber all over your child when you are sick. Wash your hands, use purell, try to keep the germs away. But if your child does get your cold -- it will be alright.
The hope is that our kids will go to school and have friends and be out in the real world. And when they do, they will be exposed to a myriad of germs. So they'll have to get their share of colds along the way, otherwise kindergarten will be a huge shock to their system.
HUGS to you, I know how hard it is!! I didn't really believe others when they told me all this when I was first learning about this sucky disease. I thought I had to keep my daughter away from everyone (including my 2 boys) -- but that wasn't realistic and I realized it wouldn't make for much of a life anyway. My daughter is now a very healthy (despite her colds and one CF exacerbation), vibrant, fun, smart and beautiful little girl.