Thanks to everyone for their replies! I feel a lot better now. Let me add a little more context to the shots.
I was one of least five other people taking pictures in some capacity. Teachers, local newspaper photographers, and volunteers were using smartphones and stand alone cameras. Someone had a Canon 40D.
I signed in at the school office as a visitor and wore a 1" x 3" school visitor sticker.
I did not receive formal permission, like a signed document. The PTO board was asking who would take pictures to be used in newsletters and the yearbook. My wife, who is PTO president, said that between me and another mom we should have plenty of photos. Everyone was happy to know I would be there.
I walked with the kids in the open. There was no secret of my presence. Kids, of both genders, would shout out to me and ask me if I could take their picture. I obliged and indulged them even if the lighting was bad. They wanted the experience of getting the picture taken and I did not want to deprive them of the excitement. Some of the shots came out good, actually. One of the volunteers working at a snack station is on the yearbook committee. She asked me to take a group shot of four sixth grade ladies that dressed up with ribbons in their hair, crazy face paint, tutus, and wacky knee high socks. Do a Google Image Search for "
color run tutu" and you'll know what I mean. They were thrilled to know I was going to photograph them.
After the event, I stayed to help clean up. The principal, who participated, gave me a hearty slap on the back and asked if I got any good shots. "300!" I told him and he said he cant wait to see them.
My coworker pointed out the shots that were of upper grade ladies. The ladies in the tutus were noticed along with a different upper grade lady in a tank top, running but turned 3/4 to face me, arm outstretched, waving a peace sign.
I was going to deliver the album to a secretary at the school office and ask her to deliver it to the principal.