Hello,
First of all I wanted to say the best of luck to you and your parents. I know you are in a difficult situtation right now. Went through the same thing with my little sister (19).
You kinda feel responsible for everything because your the oldest and your parents kinda expect it from u?? I did anyway. Just wanted to say you can only do your best, you are no miracle worker.
I agree with some of the members here. She won't listen to your parents. This is a difficult age, the age where they rebel and search for boundaries. These boundaries sometimes conflict with their own goals.
The key word in this situation is COMPROMISE. Tell your parents they shouldnt say no to everything she wants. That way she will feel there is no gain for her in obeying your parents. Their has to be some sort of win-win situation. Like for instance she wants to go to some party. In this case your parents could agree only when she accepts the conditions. The conditions could be 1. you or one of your parents drive her there to make sure she gets there in one piece and pick her up to make sure she leaves in one piece. 2. Curfew..dunno how its spelled. Like for instance the party is on weekends from 9 pm to 2 am. They could say she's gonna be picked up 11.30. This is an example of a good compromise. Without exepting these conditions shes not allowed to go. That way she will have the choice. Obey and go to a party. Or disagree and stay home.
To inform her about the use of alcohol and drugs and stuff you could take her to a rehabcentre. Just to talk to an addict there about the consequences this stuff had in their lives. Maybe a good conversation will open up her eyes. She needs to see where she is going with her behaviour and needs to make a choice for herself not become that kinda person and act on that.
I believe beating children is not a good thing to do in this situation. Whatever loyalty they have to the parents dies out. Without this loyalty they will feel no guilt when their doing something bad. And guilt is the brake on the vehicle called puberty. In this situation it is important to talk to your sister. Find out why she's acting this way. It seems like she is running away from something. Maybe something happened in the past between her and your parents?? There is something she finds in her group of friends that she lacks at home. It is important for you to be there for her. I can imagine she feels alone right now though she lives in a house full of people. Just because no one understands her.
Chores and taking away TV and such won't help I think. This way she will have even more time to think about what she will do next and how she's gonna get there. The change has to come from within. No punishment is gonna stop her. Her motivation to go out and do stuff is to big.
Finally I want to advise you to take care of the little ones as well. My little sister (12) had a lot of emotional stuff to take because of the 'warzone' at home. I noticed when my parents and my sister had a fight she would lock herself in her room and curle up in bed crying from all that. On other days she would just sleep at my aunts to get away from the situation at home. When you notice they are more quite then usual you know somethings up. In this situation its best to just talk to them and take them out to do fun stuff. Though this is between your parents and your sister, this effects them as well. Its even worse since the are so little.
You have some work cut out for you. U hang in there. This is a difficult thing to solve but not impossible. I was able to win my sisters trust after a while eventough I was the "goody two shoes" and she was seen as the black sheep of the family. She hated me for that. I had to fix our relationship first before I could talk to her in a normal way. Guess you have a headstart now.

Now my sister and I get along well. Her behaviour is good, doesnt go out that much. Just busy with school and work now. And we never did get along well as we do now.
Take care and good luck