You really have to GAL and detach. You can't let what she does eat at you like this. If you can show her you are a strong independent sexy woman, then and only then she would consider that she made a mistake.
Don't just act the part, look the part!
If she wants to separate so she can date you, its a good idea, if she wants to separate to date other people, its a bad idea.
M 33 W 29 S 4 M 5 T 7 11/7/11 Separation, W moves in with parents 12/1/11 W: "IDLY, I'm not coming back, it's over" 1/7/12 D Bomb Dropped