Amy Dickinson is a general advice columnist.
DEAR AMY: My daughter has a neighborhood friend who lives down the street. They get along well, and the girl is very nice and well-mannered. The girls frequently have "late overs" on the weekends that involve pizza and movies/games. These sometimes involve other friends of my daughter's. The girls are all 8 years old. Many times when it's time for the movie, the neighbor girl says she's not allowed to watch it. This has happened with "Diary of a Wimpy Kid," "Harry Potter," "Journey to the Mysterious Island," etc. Most of the time we find something else to watch. Other times, when my daughter has invited a friend from outside the neighborhood, I can tell they are disappointed. Should I send the neighborhood girl home when this happens? We have not exchanged phone numbers with the parents. Usually the girl comes and knocks on the door. I have told her to go ask her parents if it's OK to watch the movie, and she replies that they are not home. I think she is being watched by her older siblings.
DEAR MOM: I find it surprising that you would have an 8-year-old girl in your home for hours at a time without communicating with her parents. The very first thing you should do is to make sure they are aware that she is with you. If an older sibling is in charge, then you should contact that sibling.
Once you make the parents' acquaintance and establish that they know where their child is, you can feel them out about media choices. It is a contradiction to exert such strict control over media while at the same time leaving an 8-year-old to socially fend for herself. I suspect this child isn't really conveying all of the information you need (she's only 8).
I think it is kindest to dial movie choices to the most sensitive child in the room, but you shouldn't always have to do this. The next time this happens, you can say, "I understand you can't watch this, but I think tonight we're going to watch this one, so let me walk you home."