Hi Emily,
Your post made me feel for you and your daughter very much. You have found the crux of CF, and it isn't easy. Your daughter is not likely to explode into your perception of a person with CF over night. CF is often VERY gradual, and you may not see signs for many years, and even when they arrive, you may not know the difference.
Frankly, you have two choices. You can let the anxiety of knowing that you daughter has CF drive you crazy with fear; or you can appreciate every single day that she is healthy and symptom free. Obviously, its not quite that black and white, but you will find that if you try to choose the later, you will be much more able to care for your daughter and give her the support and help she needs to fight her daily battle with CF.
If you live your life in fear of CF, this will affect how your daughter deals with her disease. In my opinion, no one can live each day expecting the worst. You have a healthy daughter. If you teach your daughter how to work hard to maintain her health, and focus on what she can do instead of what she can't, your daughter will have a great chance of living as full a life as anyone around her.
If your daughter hadn't been genetically diagnosed, it is likely that she could have gone untreated for years. Before genetic testing was available, many mild cases of CF went undiagnosed and untreated for years (including my own), often to the detriment of those individuals. Your knowledge of her diagnosis gives you and the rest of her care team the opportunity to prevent her deteriation due to lack of diagnosis. She now has a chance to benefit from preventative treatments that were not available when I was diagnosed, which will have a huge positive impact on her life. The fact that she doesn't exhibit the outward signs of CF doesn't change her diagnosis, and gives you the chance to minimize lung damage and keep her healthy.
I am 26 years old. I was diagnosed at age 4 due to nasal polyps. There were no CF specific treatments when I was diagnosed, and I didn't start daily inhalations until age 11 when pulmozyme became available (I did receive manual chest pt from age 5 on). I participated in varsity sports in high school and college, I have a Masters degree, work full time and am engaged to be married.
I have no reason to say that CF has limited me; often I feel it drives me to push myself. I work hard to stay healthy, and every time I go outside for a bike ride or a run, the hours of treaments pay dividends. CF may decrease my lifespan; it may not. We're all mortal, and either way, I will know that I lived my life to its fullest, which is more than a lot of people can say.
I wish you the best of luck in helping your daughter.
Chris
26 m w.CF