For what it's worth, my wife was a licenced chaperone, she worked on tv series too numerous to mention, in theatres particularly with Bill Kenwright productions when touring and major films on various locations. She agrees that having children in the show would have been difficult unless supervised by parents as they would require overnight supervision as well as daytime/filming time because the location was not, for the bulk of them, within reach at the begining and end of the day. I am correct in assuming that the teams all needed overnight accomodation? ( Aberdeen being some distance away) . Another problem would be getting permission from head teachers, who are under the LEA cosh on attendence, next is doctors certification that the child is fit and well. And as stated, having DBS checking only proves that your intentions are honourable or, you haven't been caught yet, as has proved the case several times.