After beating the main game, and filling in the Creature Directory, she'd ask to battle you. Not sure what the reward for beating her would be, though. I didn't think that far ahead. She's based on my PKMN Moon trainer, as is her team; Chiroptshade (fruit bat), Circuilata (blue-banded bee), Vegetar (vegemite/tar), Psyphin (dolphin), Corugosa (bobtail skink), and Thoronet (crown-of-thorns).