Sisters, can't live with ‘em and—can’t live with ‘em… When it comes to siblings, disagreements, spats, and petty arguments are just part of the bargain, and even if you grow up to be best of friends, there will be points when you’re growing up where you just want to tear each other's hair out. None of this is helped at all by sibling rivalries, the other complex family dynamics, and the topsy-turvy changes of adolescence. Still, things aren't quite even that simple or straightforward when narci…