None of us are qualified Social Councillors sorry. Talk to a parent or someone your sister trusts for now.

 

This is bad, as many other people have said tell her parents quickly.

 

1. Tell parents.
2. Call Crisis Team.
3. Don't tell her directly. Might make her more mad.

 

Ring kids helpline and ask them what to do as sometimes telling your parents can make it worst.

 

Tell your parents.

 

You're going to have to tell them about it though, help them out too. I suggest taking your sister to counselling as talking to friends isn't really going to help (If you know what I mean :/) You're going to have to tell them soon