She'd be a trainer that traveled with other trainers, with a bunch of the stereotypically "cute" pokemon, all of whom don't want to evolve. So they stay cute and tiny. And the people she travels with have stronger!1 pokemon and therefore do most of the battles, trying to protect her and leave her out of it.
And then one day she's like, "oh, btw" and all her pokemon are cute but also ridiculously strong. And she also randomly has a legendary pokemon - the kind that can change dimensions and all that shit (idk, I forget pokemon name) and then it's like lol surprise, just saved you all.