That is the problem, she is right handed, left eye dominant
It is
not a problem- just a factor to consider. And please don't let her think for a moment that it's a problem (or that there's something strange about her)!
Now, I may have to experiment, because at 10, she already is talking about competition.
And that gives you good reason to treat it properly, and give her the best solution possible.
Some things to bear in mind:
-It is not difficult to train a left eyed shooter to shoot right eyed. A shooter that does so can be every bit as good shooting right eyed as they would be shooting left eyed.
However, it is an entirely different matter trying to train a right handed shooter to shoot left handed. A right handed shooter trained and taught to shoot left handed will likely never be as good as they would be if they had trained and practiced shooting right handed. Trigger control
is that important.
-How she shoots best now is not necessarily a good way to tell what is the best way for her to shoot.
-If she learns to shoot left handed and likes shooting, and someday wants to get more serious about it, she will end up working with a coach. That coach may very well want to correct her position and teach her to shoot right handed. Very likely, she will
HATE having to learn to shoot "wrong-handed" then. It would be a shame if shooting stops being fun at the point that she decides to become serious about it.
-Maybe the worst thing to do would be to switch back and forth. It's perfectly fine to experiment for a bit- but if she spends a while switching between the two, very likely the only habits she learns will be bad ones.
If she wants to shoot moving targets with both eyes open (trap/skeet, run'n'gun), a coach may advise and teach her differently. But if she wants to do high power, F-class, Marine sniper school, or just be better than all the boys, I would teach her to shoot right handed with her left eye covered.