Unfortunately (or fortunately -- depending on how you look at it) it is possible for a person to go 14 years without any CF symptoms.
While the 44 is in the borderline area (which still usually means positive) and the 78 is clearly positive, it seems quite possible they will find two CF genes in the DNA test (assuming that they test for all 1600 of them rather than just a smaller screening, testing for only 89 or so)
You can read my blog for more details, but the short story is, my kids have very few CF symptoms. Our daughter was misdiagnosed because her sweat test number is 38 (normal) and she had so few symptoms, nobody thought it could be CF. My son didn't show any symptoms until age 21 years. Both kids are pancreatic sufficient so they do not have any digestive or weight gain issues.
I have met a lot of people online with the same gene combination as my kids Delta F508 and R117H -- more often than not, all of these people have late onset symptoms, are pancreatic sufficient and generally are in very good health.
So in short -- yes I think it is very possible for someone to go 14 years w/o symptoms and still have CF. I'm sure if you started your own post and posted it in family and adult section you would get a lot of replies similar to mine.