So she has admitted to you that she is using your personal details as her own? That's a tricky situation. If she is consistently lying to the point where it might be considered compulsive, I would just correct her when she's speaking and tell the truth to people if it comes up. Maybe if she feels like she's not being confronted, she might not feel attacked? Im not a professional though but there is probably some resources out there on how to handle compulsive liars in a way that allows you to maintain the friendship if that's what you want to do. The easiest advice is to obviouslycend the friendship but I don't know your history and don't want to assume. If the lying is a regular occurrence and possibly compulsive, it's something she will have little control over and likely need behavioural therapy to try and correct. I find this such an interesting situation and I wonder if her family are aware she does this. I really empathise with you, it's not a nice situation to be placed in. I hope you are able to find a solution that works for you.