Nicknames

We've been trying to decide on nicknames for ourselves. At the moment Katherine is Kit or Kitty obviously. But for Charlotte we've got Barnett, Shardo, Charlie, Sparrow or just Charlotte. For Alexandra we've got Alex, Anya, Sharckonkhan, Sharcky or just Alexandra. We want to know your thoughts on what we should be called and now you know who we're refering to when you see all these random names.