If you want to go no contact, then go no contact. The actions is more important than the words. Plus, if you tell her this, and then renege or your commitment, you will look weak.
Is emailing back and forth with her "working"? It seems like it has some positive for your sitch and your desired outcome.
WW's are often involved in an internal turmoil, their actions are unhealthy, and it weighs on them. She may be depressed, who knows? The biggest thing is that you don't know and you can't help. Her circus, her monkeys. Give her time and space while you work on you. Seriously. Go have fun, go learn something, be social, read more, walk through park, run, workout, something.
H 34 W 29 BD 3/12/18 Divorce Busted Spring 19
It is not things that bother us, but the stories we tell ourselves about things.