Hi there! I agree with the others.....PFT's can differ day to day, depending on how you feel..If you have a cold or other issues, it will throw it off. An FEV1 of 70 is on the low side, but not terrible, so that's a good thing. I know being a mom that you are on that doc like white on rice about the breathing, meds etc...LOL, I know I am about my kiddies (the both don't have CF, just other health issues). Just keep a good eye on it, alot depends on how your kid feels too...I hope I have helped. Hugs, Cepaciagal