Yes, you are spot on and an important coach told DD and coaches not to worry about vault, it will come as she gets bigger, taller, heavier. Also I heard the announcers on TV at the Nastia Liukin Cup say that Chow follows this same line of thinking, that is, not to rush vault.I've got no horses in this race, but I have seen some snarky comments towards another mom with a fast tracked kiddo so maybe there's something to it.
If this child is still vaulting a handspring, so what? Her size would be a great disadvantage to her on vault and I think it's better to compete a handspring and work technique than to chuck a Tsuk or Yurchenko too early.
If this kid can't put it together for l9 next year and has to repeat 8---that's fine too. Even if you think Mom counted her chickens before they hatched---that doesn't hurt us. If the mom's worst fault is to squeeze into conversations her daughter's age and level, that's not so bad. I've never seen the mom be anything but supportive to others, so even if she toots her kid's own horn, I don't care.
The little gymnast is talented----level 8,9, whatever.