I am so sorry that she's still acting out. She's playing the distance/pursuit game w/you. Some of them even go one step further being nice for a while and then turning nasty...all in the name of hooking you back into their circle. I think you've got the right idea of just being yourself. I'm sure you are getting more than tired of the games because when you have one living under your roof, you can't get away from them and their antics...it's right in your face 24/7. Please try to get out of the house a bit this holiday season even if it's just to go to the coffee shop or take a walk or a drive. You need a break every once in a while.
Bless your little one's heart. He senses that things aren't right and those notes are his way of trying to cheer you up. Give him an extra big hug today.
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.