Well, Minette Walters is a British writer of detective novels. I always thought that Minette was French in origin, like Jeanette, Colette etc. Derived from Mina or Minna perhaps? I have read that Minna means "love, affection". Minetta *looks* Italian (like Elisabetta, Giulietta etc.).
Anyway, I think Minetta is a pretty and uncommon name. Do people ever use a nn, like Minnie or Etta?