The narrator wishes she could tell us that, with three daughters married, Mrs. Bennet became sensible, friendly, and happy —but no.
There's good news for some of our other characters, though:
Mr. Bennet misses Elizabeth a great deal and makes many surprise visits to Pemberley.
Mr. Bingley and Jane buy property near the Darcys, as far away from the other Bennets as possible.
Kitty improves by spending a lot of time with Jane and Elizabeth, and Mr. Bennet keeps her from visiting Lydia (who promises lots of dances and young men).
Mary stays at home and grows out of her bookish ways.
Lydia writes to Elizabeth, saying that it is so wonderful she is so rich and hopes that, when Elizabeth has some spare time or nothing better to do, she will think of them (and give them money).
Elizabeth decides she has many better things to do and writes a firm response to Lydia to put a stop to such requests. She does occasionally send some money, and Darcy helps Wickham out in his career—although obviously he's not welcome at Pemberley.
Lady Catherine eventually gives up her grudge, as does Miss Bingley. (Ten thousand pounds a year will win you a lot of friends.)
And the Gardiners are always welcome: they're the ones who brought Mr. Darcy and Elizabeth back together again in the first place.