My Ex Wife Is Showing Alarming Behavior And Need To Know If I Should Get The Authorities Involved.

My ex wife and I separated last year and she has been acting like a child. She is constantly smoking pot in the house with my children (m7 and f3) in the home. Everytime I go to drop them off or pick them up the house reeks of pot and smoke is dense in the home. Last night she showed up to parents night at my daughter's school and even her vehicle was so dense with the smell it was nauseating. She has a lot of traffic at her home and when I call to speak to the kids there is so much background noise I can barely hear them. I hear her swearing and yelling and her friends are also making a tremendous racket. I don't believe this is a good environment for my children but don't know how to go about talking about this. When I do try to bring it up she says it's none of my business what she does in her home and I can't do anything about it. I don't want to keep her from the kids but I also want them to have a safe and stable home. Am I in the wrong or does this give me a real reason to be concerned? How can I go about this without us having a legal custody agreement? I think a wellness check would be good but I don't want to waste the officer's time or go out of bounds and it be harassment. I just want what's best for my kids.