I don't know anything about the 2nd mutation, you may want to post this question under the family section -- I believe there's a section in which you can ask Steve from Ambry (genetic testing) about specific mutations.
Mutations can be tricky -- members within a family, who have the same mutations, may have differing symptoms. Some people have more digestive issues, some sinus, some respiratory.
I assume you've been referred to a cf clinic..? Now that you know your child has cf, it's important to see a CF specialist, be proactive in terms of your child's care so she can lead a normal active life. DS is pancreatic insufficient and therefore needs enzymes to digest his food. We also do chest physiotherapy and nebulized medications to keep his lungs clear.
Years ago DS was diagnosed shortly after he was born with a bowel obstruction caused by meconium illeus -- no family history, no lung issues, I'd had a normal pregnancy. Was a complete shock. We were overwhelmed, went thru a whole range of emotions. We took (take) things day by day. Got into a routine in terms of care. Today DS is a normal, happy elementary school child who just happens to have CF.
Sure, we worry about the future, worry he may get ill, but it's also important to have a normal life, enjoy normal childhood milestones.