I also have basically done the same thing that you have roof, with letting W hang herself on her own rope, but I also made sure to consult a lawyer, just to make sure of my rights.
I am glad that I did, because I have far more knowledge about the law than STBXW and now she is in a real bind as she has basically put me in the position or having the upper hand should custody issues arise.
You need to protect yourself and your children. I didn't file, but I was sure ready when she did. It actually tipped the scales on her and she actually learned something from it.
I guess my main message is get the protection, and then wait. It takes patience. Once she messes up enough, you will be prepared if you need to be.
Good luck!
M:35 W:33 M: 5 yrs. Daughter: 2 yr .7/11/10 D Final: 8/7/12