I think she means Cystic Fibrosis, my daughter also had a little friend with cf, RUBYLEE, she was only 7 years old when she died, i have her on video at my daughters birthday parties, it so sad, she was such a cutey, its a real cruel disease.
My heart goes out to you, loosing a friend this way is very difficult, try to remember the good times you had with her, and if your'e a believer in the after-life, that she is safe and well again in a very special place.
HUGS to you.