I understand your concern, but I agree with Jo, you might as well have posted on a big neon sign or sky writing..."I think you are a bad mother!" What's done is done, but you've got to find a way to curb your commentary about her parenting. And whether your son is right or not, mentioning "S6 told me" is a definite no go. YOU HAVE NO CONTROL OVER HER. Unless you get full custody and she has supervised visitation you can't control those things.
But as you said..it's in the past. But are you going to learn from it?
Sorry so harsh, but these parenting criticisms are going to kill your chances if you continue.
In the end, it's not the years in your life that count. It's the life in your years. Abraham Lincoln
It is hard to fail, but it is worse never to have tried to succeed. Theodore Roosevelt