This will be quick because i've got to get back to work, but let me just say your blog, "childofprayer.com" is wonderful. The Lord is good, and there is a reason and place for every child. I will read more and comment later! I so commend your courage and faith for taking this little girl on ... and I have some good news.
As a person who actually has CF, who has lived to the ripe old age of 52, I'd like to share a couple of things. First, just know that there's still so much they don't know about the ends and outs of this genetic disorder. It isn't always that complicated. You mention her cf is "well controlled" and it could be (dis-pite her mutation) that she has a mild case, or one that can be controlled with diet and exercise. Exercise is crucial. It not only helps the lungs but digestion as well. See if she gravitates toward a sport or pastime (like gymnastics or dance) that she loves. Then let her go after it. That's how mine was/is controlled.
As far as the diet goes, even with enzymes, eating a very healthy diet (not this whole-milk super rich calorie laden inflammatory stuff) is the key to having a normal life. Back in the day, they didn't have pulmyzime, the vest, any of that, and the "cf diet" was NON-fat or LOW-fat, high protein. (I was never allowed ice-cream, french fries, any of the stuff they tell kids now to eat.) Yes, I was slender, but so what? I had tons of energy, perfect lung function, no hospitalizations. I lived at the pool in the summer, later became a life-guard and swim instructor. I know now that being in the chlorinated water regularly was key for my sinuses and lung function to stay normal.
I've been in the hospital 3 times in my life, the last one in 2008. I attribute that (again) to having access to a pool growing up, and starting dance in college (still go to class 3-4 times a week.) As I was never allowed high fat foods as a child, I didn't develop a taste for them; instead eating lots of home-grown stuff and farmers market fare.
Can you start a small garden? Even a patio one gets kids to understand where their food comes from, and if they grow it they'll most likely eat it! Good for getting healthy eating habits going that may extend her life, and yours as well.
Also get a good juicer. Important investment in time and money, as this will be your "keep her out of the hospital machine." Carrot apple/orange is the best and keeps lung infections away. Plus, good for you and your husband too. My husband is 53, we live on an farm, with an animal rescue and full-time careers besides... and are not "sick" like our "normal" friends in their 40's and 50's.
I'll be praying for you, and pm me anytime ...there are several other things I do that they won't tell you about in a clinic...but they work, that I'd be glad to share. (So much for being quick! )
All the very best!
