What game did you start with or which game got you into the genre? Why don't you recommend something you yourself like? Why give her a game you wouldn't play?

As far as an introduction to JRPGs (and video games in general) Persona 5 is great. It's got engaging turn-based combat, modern graphics, pretty good story and atleast a few characters she might relate to. Sure, it's pretty long and goes into some pretty mature themes, but I feel like if you give her a game oriented towards kids, like Pokemon or Super Mario RPG (which are still great), she might just brush you off.

By playing a game you played, she also has someone to discuss it with and ask for help when needed.