We haven't heard of legal cases over these events, but they definitely have been controversial in various communities over the last several years. A common issue has involved single moms who want to attend the father-daughter dance with their child. Another concern has been the names, which don't always reflect nontraditional families. A girl with a single parent might want to bring an uncle, for example.
This isn't legal advice, obviously, but in general we don't see a problem with these types of events. I'd recommend if you do hold them that you be inclusive -- don't turn away anyone who wants to attend, create names that are inviting and don't seem to exclude nonparents, and create equivalent events for boys and girls (don't have a dance for girls and a field day for boys, for instance).
We have a current Facebook thread with lots of alternative names for these events. Good luck, and please let us know how this turns out.
- Craig
Links in this post:
lots of alternative names for these events: https://www.facebook.com/PTOToday/posts/10155821749935224