I was just thinking about this as part of trying to figure out what JA meant by a "large" party. In ch.5, the Omniscient Narrator tells us casually that Charlotte is the eldest of "several" children, which my modern dictionary defines as "more than two or three, but not many". We know that Charlotte has at least two brothers and two sisters, including Maria.

In ch.39, we find that "their party in the dining-room was large, for *almost all* the Lucases came to meet Maria and hear the news" (after the girls' return from Hunsford and London).

We are told that Lady Lucas is busy questioning Maria about "the welfare and poultry of her eldest daughter", while "Mrs. Bennet was doubly engaged, on one hand collecting an account of the present fashions from Jane, who sat some way below her, and, on the other, retailing them all to the younger Miss Lucases". I conclude that there must have been at least *two* Lucas daughters besides Maria and Charlotte, because Maria is busy talking to her mother, and anyway, why would she need to hear about the London fashions third-hand from Mrs. Bennet when she has been in London twice in the last six weeks herself (if only overnight), and spent time with Jane and Mrs. Gardiner?