My Kelly/Kelleys started out in the 1700's spelling their name Kelley and it would appear that my grandfather changed it to Kelly in the 1880's. Some of my Kelly relatives still spell it Kelley. We are and as near as I can tell always have been Irish Protestants. If the reason your elderly relative gives is valid it has probably been lost in obscurity. It appears now to be a matter of preference. I am sure that census takers took all sorts of liberty with spelling all sorts of names. My Baer relatives are just as likely to end up Bear. Maureen