Stop trying to mind read! She may have changed her FB name so that you don't know what's going on w/her. Maybe she doesn't want others to see what she's doing. Just because she's dropped the married name, it doesn't always mean signal that the marriage is having problems. You need to advise your friends that you do not wish to know what she's doing. This bit of info doesn't help you to move forward.
Another thought, she may have done this so that it does get back to you. Why? Even though you were in a good place lately, it could be that she's not comfortable in getting closer at this time. She making every effort not to feel that warm and fuzzy feeling about you and the relationship and one way to drop ice on any "expectation" that you have about how things are right now is to do something drastic such as dropping the married name on FB. She knows that people will tell you about this and knows that it will put you in a tailspin. Let it go. It's just a minor name change and who knows, it could change again in the next week. BTW, I wouldn't say one word to her about the name change. You don't want to let her see you sweat. They do all sorts of crazy stuff and until you've got papers in your hand or have heard from her lawyer...I wouldn't let this blip on the radar rattle me.
Breathe! Keep the focus on you and your son. He needs you now to help him w/his homework. He's going to pick up on your anxiety and stress so you need to breathe and try not to think about what she's done.
Now....BREATHE!
Sit quietly, the answers will reveal themselves when you least expect them to. The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.
