It is an anynamous program. Short of possibly a judge, which I haven't seen in five years, one thing that is banged home is that who you see here, what you say here has to stay here. Right or wrong we have no rights to where our over 17 kids go or what they do. Rehabs maybe if the patient signs permission.
Nobody would go to AA or NA if their family was told of their attendance. It is the anyamynity that makes it safe. The leaders are all volunteers. This is not the program you want if you expect verification.
Now you can follow her and see that she went in but not that she stayed.