What symbol for the confused?

I was walking through a parking lot today when I saw an SUV with decals of four crosses affixed to the rear window. Two of the crosses were large with mom and dad names under each; two were small with child names under each. I told my wife that I would like do do the same thing on my truck but with an atheist symbol for me and my two sons. However, I would need to invent a symbol for my confused catholic wife. Perhaps a big question mark. ...she was not amused.

Plus, she was not aware there was a symbol for atheists. When I told her about it she laughed.