When Your Teen's Best Friend is a Negative Influence

"I am reading and reading your eBook, and I like it so far - makes a lot of sense - but the biggest problem for me with my teens especially the 16 year old girl is who her friends are. She has one best friend, and doesn't seem to hang around or call too many others - only one or two on the phone. But this girl is NOT one that is a positive influence in my daughter's life. While she is basically a sweet girl, she has had problems with drugs (in rehab type program) smokes (and now so does my daughter) has run away from home over night she is depressed and says she takes meds for her mood swings as well, and her parents that aren't as stable as would be preferred - and most sad is often accused by other kids of her "cheating" with my daughter's boyfriend, which kills my daughter but she always ends up believing her or at least saying so....."
 
MORE... 

How do I get my over-achieving daughter to slow down?

"I have taken the quiz and surprisingly found that I was a severely over indulgent parent. This angers me because I didn't think...