kiddo has never bothered me - - actually, I haven't really known anyone who uses it on a regular basis - - but on a similar note, a lot of women are bothered (actually, they tend to go ballistic) when they hear themselves (or others of their gender) referred to as girls
Not a peeve of mine at all, I tend to refer to all females as "girls" but I know there are females who feel it should only be used for females under 16 and if they're 16 or over they should be called women. Or maybe "young women" if they're under 30 or something. I don't know.
I just call 'em girls.