My daughter, Britt, 17, has had asthma since very little as well - she's been doing a lot better since puberty when the allergist said a lot of girls have a tendency at that time to out-grow asthma. She's not outgrown it, but it has seemingly gotten better. I think in Britt's case, she's been in band and blowing a trumpet and now a baritone, that is what has helped her tremendously to build up her lung strength. So if Cait's in Yoga already, that is bound to help her lung strength, because I know they use breathing techniques with that as well!
Best wishes and Hugs to you both!! Teri