Be careful trying to interpret her actions. You're likely to be wrong. You could ask her out for a drink? Then she couldn't invite your son.
What's the rush to make a move? Can you wait for her to pursue you? Then you would be more sure. Keep being you. Be the person she'd be a fool to pass up.
I feel for you in your situation. I'm very confused in mine right now. OM may be out of the picture but I cannot tell. I'm doing more waiting in limbo and trying to stay focused on me and my kids. When I allow myself to become obsessed with what my W is doing it just breeds pain within me.
Me46 W46 M25yrs T29yrs 4 children ILYBNILWY 1/30/17 PA confronted 3/6/17 Separated same house