My mom can write backwards and upside down in beautiful cursive. DD6 can also write backwards and upside down but not in cursive. (She also practices her spelling words by spelling them backwards wink )
DD11 can also do this, as well as read upside down, which I do a lot as a teacher and it floors my students when I do it in front of them. They then proceed to try it and they can't. I find it amazing that it is not an easy thing for most people to do.