I have an underage friend who is making some pretty poor choices in her life. For over a year now she has been sneaking out of her house at night when everybody is asleep, and getting picked up by an older guy that she met online. She does and sells drugs, sleeps around, self-medicates herself for depression (and God only knows where she got those pills), and lies to every single person who has ever cared for her including myself. I know way more about the situation that I care to but the problem is that not too many other people do. I am very good friends with her older sister and I know that she needs to know what is going on but I do not know how to tell her in a way that will make her understand the severity of the situation.  I also do not know how much I should tell her because I do not want to lose this person as a friend but then I do not want to be visiting a friend in a morgue either. I have already tried somewhat talking to her family with no success. They seem to care one moment and then completely forget that the whole thing happened the next day. It is so frustrating. If you have any advice as to what I should do please let me know. At this point any advice would help.