Why is my friend a psyco?

one of my best friend called Robyn have been lying so much! She lied about her having a older brother, that her neighbour killed someone, her “ boyfriends” and there are so many things she lied about! I know that these are all lies because I have proof for every one of them. Im not gonna go through all the lies because its gonna take me like 1 hour to finish typing it. So me and my other friend Kelly went to one of our school teachers about it. We really had no choice because we tried talking 2 her about it and she got all mad at us. What was really stupid was that she told COMPLETE different stories to different people and told them not to tell anyone. But they eventually told me. Which is why I think she needs help. So my teacher already talked to her about it and I think she is getting counsiled for it. Am I a good friend or a bad friend? I have been ditching her a lot because she just annoys me. Whenever she says sth, they all seem like a big fat lie. I just want to get out of this drama.