Right now if she was a boy she would do better at a regional level - just because of the sheer numbers of girls at competitions at this age. (Last year 12th out of 50 odd in the region for girls, only 9 boys entered - sounds like a good way to bump her up to the top 10)
As she moves up the age groups this is less of an issue. Around 10 the really talented ones move to elite, and leave the talented-but-not-superstars at the top. Gradually over the next few years the numbers will even out and the competition get closer as some move up faster than others. Once they get to 12 it’s usually so few they get lumped in an “under 16” category.
Meanwhile the boys get bigger and stronger, so unless there are only 3 in it, she won’t have much chance.
Has she tried DMT? Often done alongside trampoline and not popular so very low numbers.
As to transgender gymnasts, i’ve only known two. One personally, one on the coach grapevine.
The vast majority of girls drop out at puberty anyway. It’s not a great hobby unless you’re in it very seriously, or you’re lucky enough to find a coach/club that will develop non-elite gymnasts over 12.