Because talented people among us practice the pleasure of "projecting," we have a booming industry in sequels and prequels. What is "Projecting?" Continuing the story beyond the author's intended finish with your mind's eye.

The subject of my favorite projecting reverie in Emma? Why Emma of course! I think the story ends where Emma begins to develop into the role she was meant for. Some back ground for my point:

We learn Emma has been mistress of Hartfield from a young age. She apparently doesn't take a lot of interest in music, reading, needlework, and the domestic arts. So what is one of Emma's strengths? leadership and social influence. I'm inclined to think Emma is somewhat bored with the usual feminine pursuits of that day but she really begins to flex her wings in leadership and social influence, in spite of her naivete' and selfish motives.

Mr. Knightley, I think, has been fascinated and infatuated with Emma since she was a child because with his judgment and powers of observation, he sees Emma as truly a "diamond-in-the-rough"...capable of marvelous accomplishments, once she matures.
He declared himself, in speaking of Jane Fairfax, that he liked an open temperament. That perfectly describes Emma: Beautiful, intelligent, and charismatic.

In projecting out what may become of Mr. and Mrs. Knightley, and what I have observed above, I think Emma and Mr. Knightley together will just soar above Highbury. Under the loving guidance of Mr. Knightley, Emma will become the patroness of Highbury and the surrounding environs and she will grow in goodness, generosity, kindness, tolerance, and grace. Mr. Knightley with his precious Emma at his side will become more light-hearted, relaxed, and more socially oriented. There will be more (gasp) dancing, gatherings, parties, outings, dinners, and philanthropy. Mr. and Mrs. Knightley just continue to rise.