Firstly what you said in this post sounds perfect. i would facebook her that exact statement and let her deal with it the way she wants. My first response was to say that it would probably be very healing for her to hold your little man and have a good cry! It will probably be as your son grows that she will feel the greater pain. 1st birthdays and the like....

Good luck and i am so sorry that you have to deal with this at this time too!