The word chit, used to refer to a saucy or impertinent young girl, is commonly found in the pages of hist-ro. Our rakehell hero might raise his lorgnette while admiring our heroine, “an impudent chit”. Or he might tell his mates down at the club that he met “The most peculiar chit.”
So we guess the definition from context, soon forgetting our first run in with the word.
But where does it come from?
According to Webster’s, the origins of chit come from the Middle English word for kitten or cub (chitte, kitte) first used around 1578.
Join me in a collective groan…oh how ignoble to be always compared to a feline!
Adding insult to injury, the reduplication of chat first used in 1605 was chit-chat. While etymology experts suggest it simply is reduplication I think it might be a combination of chit and chat…
It would be interesting to find the original usage.
Regency Reader 
Oh I did a post a while back on my blog in the ‘historical trivia’ section about the meaning of the word ‘Chit’.
Pop over and have a look http://graceelliot-author.blogspot.com