Acording to a link in the TPM article, it seems Randal Terry and Operation Rescue also decided the children’s school was an appropriate place to hold one of their protests. Back in September:

reuters.com

WASHINGTON, Sept. 15 /PRNewswire-USNewswire/ — The following was released today by Randall Terry, Director, Operation Rescue Insurrecta Nex:

On Thursday, 9/17 and Friday 9/18, various pro-life groups will stage protests at high schools from Noon to 1:00 P.M., showing pictures of aborted and healthy babies - the same pictures Jim Pouillon was showing when he was gunned down.

One protest will occur at Sidwell Friends School in Washington DC, where many
high powered politicos send their children.