Bad Fanfic Friday: "dean and sam winchester sister story"

Sam and Dean have a Mary Sue sister? Did she just get spanked by their father?! I don't like where this is headed. Oh please, please don't let there be any Win-cest (see what I did there? Apparently all the cool kids call it that. Cool kids, you guys are gross).
As if Supernatural wasn't angsty enough, this writer's gone and added a girl of questionable age with terrible taste in clothing (don't you worry, she includes links for every outfit). I'm tree chapters and two spankings in, and I'm ready to quit Supernatural for good. I don't think I could handle flashbacks of this story abomination.