She is just being diagnosed later than normal if she actually has it. Cystic Fibrosis is a genetically inherited disease. This means you are BORN with the disease, you don't just develop it out of nowhere. It is part of your genetic make up, because you have an ion channel protein that is not working properly or not present at all. A person who does not have the two copies of the inherited recessive gene CANNOT have CF, but it could be another similar disease (similar symptoms) and diagnosis may take longer. The symptoms can vary with different individuals, just like anything else. Some have very mild symptoms where as other people have problems as soon as they are born, and great difficulties throughout adulthood.
