I like
Kitty as a nickname for
Katharine more then a full name. It sounds more feminine then
Kit, which would be a cute nickname for a little boy. I would probably call a girl
Katharine with that spelling, though
Catalina is nice for a form of
Katherine. I don't know how you manage to go from
Catalina to
Kitty though, even though it is related to
Katharine.
"Wanting to be someone else is a waste of the person you are." -
Kurt Cobain