My Oxford's World's Classics edition of P&P has a note that "the distinction between vanity and pride is made in Mrs. Chapone's "Letters on the Improvement of the Mind" (1773), Letter IV, "On the Regulation of the Heart and Affections", where *pride is associated with men, vanity with women*. There is an oblique reference to Mrs. Chapone's work in ch.8" (when Darcy talks about the improvement of a woman's mind by extensive reading).