OMG she sounds annoying...tbh I wouldn't call this pathological lying. From what I've seen pathological lying is generally where the person tells lies about themselves and usually fairly believable lies also they don't usually do it with the intent to cause discord or drama. In the case of someone telling really grandiose stories the disorder would be something like delusional disorder...But she's just spreading rumors and gossiping about people because she's bored or enjoys causing trouble. Something a lot of teenage girls do but she should have outgrown it a long time ago. I would go to your boss about it and say her behavior is causing conflict in the workplace.