And I second the idea that dance is never wasted. I'm in excellent shape for a desk-bound mother of two, and my dance training not only makes it easy for me to do Scottish Country Dancing, it helps with all sorts of other things - like posture, breathing for singing, and my horseback riding and dog handling. I know that sounds odd, but the balance and what I think is called prioperception (the sense of where your body is without looking) are directly translatable to riding. Also, in my dog agility handling I have a better sense of where my body is in relation to the obstacles and my dog, and I can do quick turns and so forth without falling over (something that not everybody can say . . . at every trial we lose one or two people tripping over a jump or just falling down, a disqualification in either case.)
I do tell my self that as well. I homeschool so ballet IS her pyhsical education and a darn good one at that. Strength, flexibility, aerobic, and theater(kind of)too. It will never be a waste to get so much out of her dance experience.