I am so sorry to hear about your baby carrying the disease. A friend of mine just found out her son may have CF and she too, is terrified. I have done some research on the disease and it is not as bad as it used to be to be diagnosed with CF. Technology has come a long way as far as treatments and medication. There are breathing treatments, excercises, and many form of medication to help your daughter.
From what I've read, you can expect your child to live a fairly long life, as long as you follow the treatment plans given to you by the doctor. If your daughter has the mild form of CF, she can live a normal life expectancy.
I know this is devastating news for you, because it has been for my friend. Your family will have to make some big changes to help your little girl. Things will be difficult and it is a long road that you face. Keep the faith and know that God only gives you what you can handle. May God be with you in this journey.