FWIW, I do not agree with sending the letter to her family and close friends. This makes you appear desparate, vindictive, and controlling. What do you really expect from them? Do you think they will be in your corner supporting you? No, they will support their friend (your W) and their daughter (your W), but what you see as the M, they see simply as "you".
If you feel that the time is now to send the NC letter to your W, then do so. I simply wanted you to be sure that was what you wanted before you sent it.
It is not about what you feel should work in your M. It is about doing the work that gets the right results. Do what works!