HeadFaceLeg: I like you already. Stick around
Facebook is actually quite good when it comes to privacy (for a website). You can easily control who sees what info.
The movie incident isn't too bad on its own, but the fact she tried to friend your new girlfriend on Facebook is rather questionable. I'm assuming they have no other connection to one another?
Anyway, I wouldn't really worry about it too much yet. If she mysteriously shows up somewhere again, then it's definitely stalking, but for now I'd be inclined to give her the benefit of the doubt.