I've always wondered whether the idea of "bluestockings" was common at the time JA wrote P&P - the stereotype of intellectual women who, as you say, were socially backward and didn't take care of their physical appearance. Now that I come to look it up (see link below), I see that the time period would definitely work!

P&P has always given me the feeling that JA was a little defensive about her heroine being accused of reading too much. Remember that the only other woman in P&P who admits to reading a great deal is Mary! (Another definition of "bluestocking" that I found was "a woman who is learned, bookish, or *pedantic*". Sound like anyone we know? ;-) I agree that Caroline did not mean "great reader" as a compliment, though Darcy did!