Hmm, maybe big sis Touka isn't a perfect angel misled by her misfortune of being born with a tragically low IQ?
Perhaps she's just stupid AND a bitch? (Instead of just one or the other like usual.)
Still would though, as the saying goes - "Girls are at their very cutest when they're almost retarded."
(Besides as worrisome as it is, she's easily influenced if you bug her enough. Such a landmine that woman is.
If you put a ring on it - You'd seriously have to sequester her into the most wholesome community you could find to keep her out of trouble.)