I personally think she looks a lot like Touko. The male protagonist looks a lot like Touya, too. It does say that two years have passed since BW, so maybe they changed their hairstyles. Doesn't anyone else see the resemblances?
Gamefreak never does such drastic design changes for their protagonists. They'd still be recognizably Touya and Touko if they were. And besides which, they look too young.