lisalisa, cool down!
She is conveniently working from home today, so that gives you time to not have to look at her at all today and chill. A bit.
You are leaving, hopefully for a much better job and place, you can afford to look 'magnanimous'. Stay very quiet and calm in front of her, do not speak unless you need to. (You can think whatever you want, but she should not know )
Do talk to your boss, and take it from there. I'm sure you have plenty of people around that have noticed her behaviour, including your boss.
If things escalate, make sure they are escalating because of her, not you. When people provoke something it is because they want a reaction, the best thing to do is not to react. That'll also infuriate her a bit more and you'll look calm and collected.