I've ranted extensively on this topic before, so I will try to keep it short for a change
The stuff they do in most elementary schools isn't math. It's basic computation, usually taught extremely confusingly and badly by people who are scared of math and want to avoid it as much as possible. In some curriculums, it's more of a language arts writing exercise than a math one. The unfortunate result is tons of kids who think they hate math and/ or are bad at it.
I suspect someone who loves/ is good at math is someone who likes to think about patterns and relationships and why things work and what cool things can you do with that. But they don't usually get to do any kind of conceptual math thinking at school. So if she miraculously thinks she might like math despite it all, find her some Numberphile videos, Martin Gardner books, etc, and let her wallow in math presented by people who love math and want to share the joy they find in it. THEN she can decide if it's for her, and maybe discover the joy that is AoPS.
