Example: What am I getting for Christmas? Her answer was "Cat's fur for kitten's britches." meaning none of your business. Grandmom was born in 1905 so it goes back at least that far.
A female member of a co-ed sportsteam that is not particularly skilled, but is necessary to fulfill the minimum required number of females on the field so the team will not have to forfeit the match.
"Henrietta hasn't played soccer before, she's the 'forfeit kitten' today...but who cares if she can't play, at least she looks damn hot in those knee socks and shin guards..."