Darkness Angel
Lover of Fate-Chan
I still think that destroying the evil team directly would be a good goal for the new girl. It could even give her opportunities to try things out and, if character customization returns, allow her to try on different outfits and hairstyles since she may use espionage and infiltration to accomplish her goals, as well as battling the evil team directly. It would also force the animé to have more of a storyline focus and, if the evil team is done correctly, still give the animé the chance to advertise the region's Pokémon by having the evil team use them rather than mere characters of the day.
So something happens to the new girl which is bad that leads her to want to destroy the evil team. I can see this working out, plus it would be nice to see her try on different outfits as will with what you've already put down.