I would wait until she initiates a conversation about her feelings & your marriage, that way you can't be looked at as forcing the matter or being pushy. At that point you could ask if *she* thought an MC could help. That way she knows you are still willing but the ball is in her court to make the decision. I would stop at that and just see if she bites. Of course if she shoots the idea down I would drop it for the time being so you won't be looked at as pushing etc. I am sure you may have tried or asked in the past but reminding her that you are still willing probably can't hurt things.
I am new to all of this so maybe some of the vets might have a different opinion but being in similar place as your wife I thought this might be helpful.
Hang in there!
Me: 30 EX-H: 37 DD: 5 Separated 6/07. MC for months, EX-H quit MC. Divorce Final 8/14/08. Trying to move on with new life.