Actually I'm not sure that Elfie is much better than Tinkerbell (or Fifi perhaps). It makes me think of Citizen Smith (Wolfie/Foxie, and not in a good way). I'm not sure I like it even as a nn, it just sounds a bit silly to me I'm afraid - the sort of name dd would have given her stuffies a few years ago (Sealie, Doggie, Lambie etc) if she had had an Elf shaped one. I guess you could pick Elfreda, but I think that Frieda or Winifred are nicer.