And I'm serious about getting her stuff boxed up NOW. You and the friend should meet her at the door...with the door locked behind you. DO NOT let her IN under any circumstances. Trust me on this. She gets in and refuses to leave, you cannot physically remove her without exposing yourself to an assault charge. If it's going to get ugly, let it get ugly outside; let the neighbors see it, because that's better than a bunch of screaming from behind a closed door where they don't know what might be happening.
In fact, if you're cool with a couple of your neighbors, might be wise to let them know what's going to go down a whatever time she'll be coming by. They're valuable witnesses should shit hit the fan...adds even more credibility to your side of the story than just having the one friend there (but still have that friend, cuz you know he's willing to testify!).