Yeah, that would be a pretty tough truth to tell the daughter, that her father was a serial rapist, who got slaughtered like a pig by the authorities later. She already has an inferiority complex as it is, due to how poorly the matriarch handled her case, so hearing that would make her feel even more miserable.
But damn, now Woo-Moon really can't just dump her and be on his merry way. Dude needs to have her live somewhere safe and leave some martial arts manuals for her to peruse, while he's unavoidably away fighting the Muncheon bastards. Then he needs to fetch her and figure something out.