Stop trying to understand why your ex is doing what she's doing; she didn't logic her way into acting like this. When she left, it was on impulse and for shallow reasons; that's exactly why she's coming back now too. For whatever reason, she is not thinking through some really major life decisions, and you'll drive yourself nuts trying to make it make sense.

It would be best to start routing communication through your divorce attorney. You also need to provide your lawyer with whatever documentation you have of her behavior. What she is doing is harassment, and the fact that she's deliberately circumventing your attempts to cut off communication gives you a strong basis for a restraining order.

You say you're afraid she'd lose her job if you got a TRO: does she feel the same way? Because maybe that's the exact consequence she needs to be facing in order to stop this behavior. And if you put this in the hands of your divorce attorney, maybe her lawyer will rein her in once they become aware of what she's doing (this behavior is never good, but it's a particularly bad idea while smack in the middle of divorce proceedings). Somebody needs to give her a wake-up call, but that person isn't you.

Stop humoring her or trying to be nice; she is not giving you the same consideration and is clearly no longer interested in an amicable divorce. If she wants to take this to a nasty level, she's giving you a hell of a lot of leverage against her along the way; might as well take her up on it.