What to do for a family member who is doing all the wrong things then leaving you to take the blame.?

i have this cousin who lives with me and she is into all the wrong things. she does drugs, is always sleeping around with people, gets into many fights and basically thinks she is invincible. Every time she gets caught doing something bad i always the adults always find a way to pin it on me. i have tried many times to confront her about it but she doesn't listen to me. she didn't used to be like this but ever since 3 years a go she has changed. i love her and everything but she has pushed me to a point where i can't take her crap anymore. please help me to resolve the situation.