Hello petite39,
Indeed, she is jealous of you, of what you were able to give your ex (a child), she is jealous of the past, of the experiences in your past relationship, but also in the present, given that you have maintained contact with your ex for various reasons. The past still binds you, and so does the child. She is afraid that things will start again between you and that she will remain powerless, and this comes out as rage and resentment.
She needs to be reassured that there will be nothing between you anymore. It will take a little more time for her to let go and stop bothering you. If you want to get your ex back, that’s a different story, but if you no longer want to, have a discussion with her and make things clear.
I think jealousy will never stop, but at least a reduction in its intensity would already be quite something.
Best regards
Ladysally