Panel 1: Later that night, Elly is getting John to agree that it was wonderful seeing all those children's choirs.
Panel 2: She hints broadly at being a bit player in Liz's life when she doesn't know if she should be more choked up by Liz being on television or Liz singing well on stage and thus representing her mother.
Panel 3: She hints broadly at a sort of "Canada: for British only" thinking when she thinks it good that children of all nationalities can get together for the cause of peace.
Panel 4: This is contrasted by the fact that Liz has initiated a mixed-gender pillow fight in a hotel room. This raises questions like 'who is chaperoning these kids?', 'are they expected to sleep in their clothes?', and 'why am I putting more thought into this than the author?'
Summary: John and Elly never learn that their kids can't be made wonderful by other people. That's their job and they're terrible at it.