Symmetry

So Cinderella has been learning about the line of symmetry in math, and the other day she said to me, "Did you know that Spike's teeth are like symmetry"

I said, "Oh ya, thy kind of are."  amazed at how my child was grasping this new concept.  

Then she said to me, "you know what I mean?"  So wanting to hear her explain, I asked, "what?"

She then said, "You know like tombstones?"