Even though their courtship makes an absorbing story, I fear the marriage of Elizabeth and Fitzwilliam Darcy will be a rocky one. A marriage across class barriers might seem romantic, but there will be a lot of learning to do on both sides. Fitzwilliam will not find it as easy to shed his arrogance as he thinks, and Elizabeth will not suffer it meekly. He will sulk after an argument and they will not speak for days.
In those times especially, but at other times too, she will be lonely. She is used to a small house filled with five other noisy, combative women and a father whose wit cuts the air. Here she inhabits a cavernous mansion with a taciturn husband, his timid young sister and so many servants that she struggles to remember their names. Yet if she invites her mother or sisters to visit her husband becomes even more difficult, because he despises them. Of course they will eventually make up, passionately and with a great show of repentence, after each argument, and perhaps eventually a brood of children will mellow them and fill her loneliness.
I feel a lot more optimistic, though, about Emma and George Knightley. They are of the same social class, the prince and princess of their parish even before their marriage. They share the same values, both kind and generous in a condescending upper class way. And of course they know each other inside out, having spent so much of their lives together that they are almost (but not quite) like brother and sister. Her warmth and kindness make up for his occasional aloofness, while his sharp intelligence compensates for her occasional brain fades.
Nothing could be easier or more natural than for them to take their friendship to the next level. The only barrier to this marriage is Emma's immaturity. As we see from Jane Austen's story, that is nothing that a few well-intentioned bungles can't solve. Of course they will squabble now and then like all couples do, but they will always make up before bedtime.
One day the Darcys and Knightleys will meet at some ball or garden party. As they are undressing for bed that night, Fitzwilliam will say to Elizabeth, "Those Knightley's are rather vulgar, don't you think?" Elizabeth will snap back, "I found Mrs Knightley perfectly charming." They will both go to bed in a bad temper.
Emma, of course, has sworn off active interference in other people's love lives. However, she can't help remarking to George as they get ready for bed, "I don't know what Elizabeth sees in that sulky, ill-mannered husband of hers. I'm sure she just married him for his money." George will look shocked and say sternly, "Emma, you are so uncharitable sometimes!" Then they will catch one another's eye in the mirror and both burst out laughing, and he will help her unbraid her hair.