I would disagree that you are born with a "fluid body." I know of professional dancers that were the opposite of graceful until they were 13 or even 14. You can't change your body, but you can change how you use it.The body you are born with is the body you are born with. Sasha already was born with a fluid body. You can teach ballet, you can teach Pilates but if your lower back does not bend fluidly and your arms don’t move in the way of a ballerina dancer you can only teach that to a certain point. Your body is what your body is.