I would make sure ex knows the rules of the probation. She should really be the one arranging these things. Tell her she needs to arrange for supervision as per the terms of the probation and leave it up to her. If she desires spending time with her daughter, she'll make it happen.
I would also make sure my daughter knew where the closest drug AA type program is in her mom's area (sory, I don't know what else to call it. Considering your daughters age, it is my opinion that the best you can do is set her up for success on staying drug free, but it is up to her to make the decision to do so. No probation rules, supervised visitation, or limited contact with her mother is going to change that.
