The best thing is first you learn the yoga and teach your daughter. Then try to do every day along with your daughter because child can learn easily from parents and also like to do anything along with parents. Please try to avoid send her to yoga class. You will end up with spending money, also you will face problem of dropping her and bringing her back to home.

There are many video available for yoga in you-tube. Practice it..Teach your daughter. Dont complain your daughter that she will not continue if she do it in home. If you can able to continue daily then she will also continue.Remember Yoga is good for all...

I find the following yoga Video..

http://www.youtube.com/watch?v=8pXJcnal3WA

Practice it.Be a responsible Father. Teach her and continue everyday along with her.

Apart from this consult any Lungs specialist to get it cure with medication. Good Luck.