] I just had to take the opportunity to wonder if the use of Lydia's name in P&P might be a bit of judicious foreshadowing on JA's behalf of Lydia's future ;)

Lydia was a very singular choice of name. In the 5,000 relatives I have of JA only three are called Lydia - and they are all related.

Just as JA's GG uncles James Duke of Chandos married the name of "Cassandra" in the person of Cassandra Willoughby (1st wife) he also married the name "Lydia" in the person of Lydia Van Hatten (3rd wife). When he married Cassandra his eldest sister (JA's grandmother, Mary Brydges) called one of her seven children Cassandra. Of the remaining six children, five called one of their daughters "Cassandra". Mary Leigh (JA's great aunt) must have decided to triple her chances of ingratiation by naming three of her daughters after the Duke of Chandos' three wives. She ended up with five daughters; Jane, Mary, Cassandra, Annabella and Lydia.

Even more interestingly these five girls were all related to/descended from the Bennetts