Okay my wife wants me to make her a personal knife. The thing is, is that she has small hands. I want to make her a knife hat "Fits" her. Do any of you have any "formula" for determining the appropriate size handle?? Her hand measures 3 1/2" across x 6 1/4" from her wrist to fingertip of her middle finger. I'm not worried so much about the thickness of the handle (I can always sand it down to suit her) as I am concerned about the length. Any help would be greatly appreciated!!