At my gym, you have to be 8 or older to compete, but my gym trains above their skill requirement. When I was younger nothing was good especially vault because I had no power. Also when you get older it's easier to have more power but still controls it, and because she's starting at a young age she could be ahead of some people when she gets older I was in silver for two years but when I moved up I was above my skill level and went through Gold very quickly and easy now I'm in Platinum and I'm 11.
It sounds like you have a lot of great info, but you have to be 16 to post on ChalkBucket, for your protection. Come back when you are old enough.