Pirouette

Great read for 12+ girls set in the ballet world, by best-selling author Robyn Bavati.
 
Adopted as babies by two different families, Simone and Hannah have never known they are identical twins. Simone has been raised as a dancer, but she hates performing. Hannah loves nothing more than dance, but her parents see it as just a hobby. When the two girls pirouette into each other's lives, they decide to swap places and make their dreams come true.

But for how long can Simone and Hannah keep pretending? What will happen when the truth is revealed?