DS is 8 and an only child. He's pancreatic insufficient -- needs digestive enzymes and a bit of a picky eater, but basically eats what we do but with added salt and fat. At home with meals drinks carnation instant breakfast made with whole milk and cream. I know a friend of mine has to maintain a balance between her cf child needing extra calories and fat, vs. her non-cf child who doesn't and tends to over eat.
We do make sure that anyone in close contact with DS gets their flu shots each year -- grandparents, cousins, aunts, uncles, parents & caregivers. So if you and your daughters have never gotten flu shots before, you may want to give that serious consideration.
DS does vest and neb treatments 2-3 times a day, which means he gets to spend that time watching whatever he wants on tv/dvd or playing video games. It's HIS time since he has to sit there for 30-45 minutes plus at a time.
There may be bathroom issues. DS is ooooh so proud of his ability to pass gas and make deposits in the bathroom; however, girls are most likely VERY self conscious about this. Should be made embarrassed about possible accidents, smells...
Otherwise he's a normal child, normal activities, but just needs some extra things -- medications, treatments to keep him happy and healthy.