User blog comment:Numbuh 404/Nanny Smurf Theory/@comment-1323688-20130417022815/@comment-5571486-20130417095930

I always thought that was her last name actually. I know nobody ever said this, but I always had the idea that Grandpa and Nanny were "together", thus making Nanny take the last name of her supposed husband. I got this idea since there really isn't another Grandpa Smurf or Nanny in the village, and with in mind that Papa Smurf is Grandpa's son. Since both elder Smurfs were once the oldest beings in the village, I just narrowed it down to them being the parents of Papa Smurf.