Unfortunately, she's going to do what she's going to do. If you don't give her room, it's just going to push her away faster. Like IaP said, if she serves you papers, you have 30 days to respond. Use the time wisely. DB your tail off. Also, the more amicable you make it, the better the odds for reconciliation. Again, like IaP mentioned, it's less expenses anyway.
I think the better you DB, the more confused she will be when she moves out.