She has done this to you for years. As soon as she knows you want know contact, she contacts you. As soon as your life is going really well, she contacts you. I challenge the idea that she doesn't know she triggers you. If she didn't know, she wouldn't contact you each time you were happy and having a streak of positive things in your family's life.
I would call the Court Clerk to see what the procedure is and what is required to get a restraining order. That would be how to find out. Of course a lawyer could tell you, and you may need one, but for starters, the Court Clerk down at the courthouse is a good place to start. And it is free!
I hope the rest of your day is wonderful!
Merry Christmas!