WHAT IN THE WORLD ARE YOU DOING ?
Why are you even talking to your boyfriends EX to begin with?
No you are not crazy, you are right to do what you want to do and she has no right to try and tell you other wise. I admire you for what you are doing in order to have a better environment for your son. That takes a lot of courage and dedication to do that. You are a wonderful lady. Still I would be cautious around her and keep my eyes and ears open. It never hurts to be alert. Just do not let it make you paranoid.
My pleasure when I am talking to a rational intelligent person. You will be fine. And let her talk and give you all the info that she wants to. it will only benefit you if there should ever be a need. Just make sure you keep your info to yourself.