I cant advise you on how to motivate or control a teenager (if I could, my boy would have gone to the Harriers last night instead of opting out for the Xbox, lazy little etc etc
). However, I can pass comment and offer hope on the panic attack/anxiety front.
I used to MTB years ago in my 20's, but by the time I hit 30 I had stopped cycling, football, squash, purely down to motivation and work commitments. Around my late 20's i started to suffer panic attacks and was diagnosed with GAD and Health anxiety disorders (there's so many anxiety acronyms, it's enough to give you anxiety !!!). Anyway long story short, tried many treatments and none worked, finally went back to see yet another GP. This fella was a keen cyclist, been in the local paper often for charity rides, he said, so do you own a bike? if you do, it may be all the treatment you need. I did, an old Peugeot mountain bike (wish I kept it now, might be rare !!!). in desperation, I dug it out, new tyres etc and started to ride again. I wasn't cured overnight, but steadily as I got fitter, my anxiety days became less.
Shooting forward (I have a tendency to waffle on to anyone that will listen
), at 40 years old in 2007 I bought a Trek 4300 as I was going out more and more, I now have a road bike and another MTB, and try to go out at least twice a week, and my anxiety days in the last 6 years you can count on one hand.
So in summary, keep her motivated to cycle on, it may do her a lot more good than just fitness