While looking through my kindergartener's school work last night I was pleased to find this:
Now, I'm not sure how long the concept of symmetry has been taught in kindergarten, but I do know that my 10 year old did not bring home any work like this when he was in kindergarten six years ago.
About a week ago I also saw several papers in my second grader's work that covered the concept of symmetry. I would interpret this trend as good news about the "trickle down" effect of String Theory's acceptance in a more general educational sense. Of course, String Theory did not invent Symmetry, but it has made symmetry an important foundational idea.