Heads up, this might be long.
It started in grade nine. My friend and I had a friend who had a friend. They were two years older than us and were pretty shy but we got along. Eventually when the original shared friends graduated (a year later) we were constantly hanging out with the other friend, Shawna.
It was fine until she started lying. At first it was small things but then it would turn into gas-lighting. She got my other friend upset with me fairly often for complete lies but I would get over it because she would act so nice afterwards.
Eventually we joined another person because we had a class with them. We would sit outside at lunch by the volleyball court. We kept almost getting hit in the face with a volleyball so we joked about taking it away from them. Then when the new friend ended up roofing the ball Shawna went at me saying it was my fault because I had joked with them earlier.
This slowly developed and her lies got to my other friend who wasn't there that day. She would harass me in messages and spread lies. Then she turned on my friend.
She told her mother my friend had sexually assaulted her. There were ways to prove it was a lie but her mother didn't even bother to check. My friend's mom was harassed on 40 different online accounts until the police were called. The principals at the school refused to do anything.
Eventually it got to the point where we couldn't go anywhere alone in case something happened. I got called into the office for everything from name calling to insulting her medication (I take the same medication so it was a really stupid lie).
Shawna manage another friend and she would use them by sending them into the hall to yell at us to "f*ck off" if we walked in a certain hallway. When we went to the principals they told us we just shouldn't walk in that hallway.
From what we know, Shawna got no repercussions.