Scorp, 12 days sounds fair. At that time, make sure you politely give her a deadline. "W, it's been nearly two weeks, what conclusion have you come to?" If she responds, awesome, if not, "W, I'd like to know by Friday/Monday/whatever-day" giving her ample time to get her chit together if she hasn't already and removing any potential for "but I didn't know". You're continuing to give her time and space but your lawyer is ready to go Saturday/Tuesday/whatever-day-plus-1.
Me: 31, W: 29 T: 4 M: 2 Kids: 3 (SS: 7, SD: 4, D: 3) Separated, still living together: Nov 2013 Separate bedrooms: Feb 2014 W working away; kids with me: Nov 2014