I'd keep well away from her!! Tell her in an email and keep a copy!! Don't get rude or abusive or anything, lay down the facts that because she betrayed your trust etc., you no longer wish to communicate with her. If she persists warn her with getting some sort of restraining order!! I have had a similar experience and it got nasty and because i didnt keep copies of mail and texts from the cell phone i had a bit of a nightmare trying to prove my side of the saga. Take care of you!!