Well, my husband's 14 year old changed from a pediatrician to a general practitioner, had to attend physical therapy for her knee, and was in counseling for some issues she had with her dad being gone (she missed him so much, understandably).
The schools and teachers know the situation and I had no problem with teacher conferences, but when it came time to register them, they only allow the legal parent to do it.
Additionally, trying to call the insurance company ALWAYS gave me problems. It is just so frustrating. Even a temporary guardianship (if allowed) would be better than nothing...sometimes I felt the POA was useless. :-(