My advice is to leave well alone. You will be seen merely as a trouble maker if you try and advise anyone involved of Mel's behaviour. She sounds like an attention seeker, and as such is an insecure individual. If you leave well alone, someone else will eventually start to discuss her activities - in the mean time, avoid getting into situations where you or anyone close to you can be compomised. You are really best keeping away from this woman as much as possible - trouble follows people like this - don't be caught in the fall-out.