^^This. We dealt with this with my SIL (22 years old) last year. I politely told her that I will not allow that sort of behavior around my kids in the future. If she doesn't like that, then she should get good at writing letters, because that's as close as she'll get. She clammed up and has just given me dirty looks every time I've seen her since then. If dirty looks is the price to pay, I will gladly pay it for my kids to have better role models in their lives.