The airline personnel have a responsibility to stop this misbehavior even if it is the child of one of their colleagues flying non-rev. Make the complaint within fifteen minutes.

Asking for compensation via letter after the flight (or at customer service upon arrival) is entirely appropriate if the airline fails. No button pushing, no slamming of seats into recline, just tell the F/A that you are going to inform higher up of the incident.

Travel tips:
http://members.aol.com/ajaynejr/travel.htm