Supple Cow

Speaking from personal experience, being a kid and having an older sibling who doesn't like doing things with you is the same thing as having an older sibling who doesn't like you. It sucks and it makes you hate them forever... or until you've successfully completed years of therapy, whichever comes first. Basically, what I'm saying is that it is probably quite transparent to her that you don't like being around her and it certainly doesn't sound like anybody else in your family is giving her the kind of attention that a talented (and maybe a little misguided) teenage girl needs - as evinced by her constantly seeking affection from men (not boys). I'm not saying anything is your fault or that this doesn't suck for you, but the situation isn't exactly roses and pats on the back for the kid either.

My view is that Charlatan is right in that you are NOT her parent. You can't tell her what she should do with her life (nor SHOULD you). It also isn't fair to you as the only person in your family who realizes that something needs to change for her to have to bear the entire responsibility. What you can do, if you choose to do anything at all, is be her sister. If you're going to try to get her to realize that you understand her situation sucks and that you're not trying to control her life (which is the message I would suggest conveying to her), then do it genuinely. Sure, she may distrust you and curse at you the first few times, but I can almost guarantee that all she ultimately wants from you is your affection. There's nothing worse you can do than try to "help" her by spending time with her and giving her advice (or worse yet, orders) when you are visibly unhappy about being in her presence.

__________________
"I've missed more than 9000 shots in my career. I've lost almost 300 games. Twenty-six times I've been trusted to take the game winning shot and missed. I've failed over and over and over again in my life. And that is why I succeed."
(Michael Jordan)