I'm mostly joking, but has it ever been mentioned to Tokiomi that she's not actually being taught magic at all? Actually, it's not just that she's not being taught magic at all, her potential was downright destroyed by Zouken. I like to think that Tokiomi do have some sort of love for his children, albeit limited due to being a magus. Maybe he could take her back and just give her to another family or something, dunno. Kariya's being too stupid and hotheaded to not talk about it calmly with him, or even Aoi.