Ask your parents to have a serious talk with you about your concerns regarding your sister. Tell them you need their promise that they will handle this situation. Your sister is being allowed too much power in your family and she's enjoying it.
I know it takes lots of courage to ask your parents to do their job, when it comes to your sister's behavior. But you have a right to have a better family life; you're doing your jobs responsibly. Let me know what your parents do after your discussion. If they don't treat your complaints seriously, tell them you would like to see a counselor to discuss this with. Good luck.