“a more mature body give the woman an advantage”
No, it doesn’t.
I would think that the older, bigger, and stronger physically a girl gets in gymnastics, it could produce some negative consequences also. Two or three of our girls’ performances on the mat ended with them stepping out of bounds. They build up so much speed and being bigger, momentum, that it seems they could much more easily go out of bounds. A smaller, younger, feather-lite little Chinese girl would have to work very hard to go out of bounds. That is just one thing that I noticed.