Hi Paula,
I have 2 daughters with CF (also 3 sons without)... I should explain further though, my first child was a boy, no CF...my second child was a girl with CF (though we didn't know it till she was 2 1/2). To say I "opted" for another child would be inaccurate as I never intended to have anymore, but there was a birth control pill screw-up (entirely my fault) and it happened. I found out during the pregnancy that she also had CF and did opt to continue the pregnancy and have her. So, in that sense I opted to have another child. My other two sons are mine by marriage. My husband and I have sole custody of them, but I did not give birth to them.
As far as having another child after knowing the risk, it's a very personal choice and one people have strong feelings about. For me, it's a decision I do not regret. Of course my daughters are basically very healthy now. My oldest had lots of problems until she was 3 but has been fine since and is now 10. My younger daughter has never had a lung infection (though she has some sinus problems and just had surgery yesterday). As far as CF goes, it is an inconvenience for them for sure as they have to take time out of their day to do treatments, take enzymes, etc, but it doesn't rule their lives. Now that's not to say my feelings won't change later if they get sick. I can only speak from the position I am in at present. I can't imagine one of my girls without the other. They support each other and they don't feel alone. Now please don't take that to mean I would recommend having a second CF child just so the first one isn't alone, I'm just saying that is one of the positives I can make out of the situation I am in.
I wish you the best in whatever you decide for your future. There are definate benefits to having only one child (or so I am told, lol)... I sometimes feel guilty that I can't spend more time with each child cuz there are just so darn many of them... so if it turns out that way for you, it's not necessarily bad thing. I believe we should make the decisions we feel are right and try to see the positives that come from those decisions. We can always find negatives, but those do us no good.