I would like to say that reading your previous thread(s?), and this one, I respect you. You have tried to keep cool with the situation, get outside views on the matter, and tried to keep your Wizard friend out of most it, sparing him much distress.
Personally, I would have been more forward with the situation (kick her out after the first incident), but I can't expect everyone to do the same, and you've certainly done your job as a moderator well.
As a fellow DM, GM, and fa/tg/uy, I wish you the best of luck, and hope it all works out. I am having a similar issue which has been slowly building up. Thankfully, it's about to resolve itself.
Good day, sir.