Jack, sorry I missed your request for me to post the stories of my tickling my aunts' feet. I have stories about tickling, and smelling, both of my aunts feet when I was 12/13.
One night, for whatever reason, I asked my aunt the astrologer to smell her feet in the summer of 1982. She agreed to it. I smelled her bare soles, and then tickled them. She was moderately ticklish.
A bit later, the same year, I did the same thing with my aunt the artist's feet. She turned out to be extremely ticklish, as she gave a very girlish squeal, pointed her toes down very hard, and begged me not to touch her feet.
As I posted before, it wasn't long before these incident, that I realized how ticklish female feet were, after a couple of bunkmates and I tickled these girl counselors in camp who were about 19, when we were 12 or 13. .
Those were my first experiences with tickling womens bare feet, and they were great.