I've only ever met one Miranda, and she was a little brat, so for a long time I had a negative connotation with this name. However, I started to lose that association and now I like the name. I think it's pretty. I would go with Mira or Miri or maybe even Mindy as a nickname. I would avoid Randy/Randi at all costs, but I don't think too many people would naturally call her that.