Hello!

It's probably not possible for one person to end all back stabbing and gossip among groups of friends. Sadly, there are some people who use these hurtful behaviors to fuel their own sense of self worth ("If I knock someone else down, it will be easier for me to rise to the top").

The best thing for you to do is be a good example to your friends. If someone says mean things to you about another friend, don't encourage it or join in. If you're comfortable confronting the gossipy friend by saying something like "I'd rather not talk about Sarah since she's not here to tell us what really happened" that's great. But if that seems too hard or scary you can still make a statement by ignoring the gossipy comment or walking away from the person who said it.  

Another option is to talk to the school counselor to let her know what's going on with your group of friends.  She can have one or more sessions with the group (without letting them know who alerted her to the situation) to help everyone talk about what's going on, how hurtful it is, and how you can work together to stop it.

Good luck!

Kat