This is one of the funniest bits of misunderstanding I've ever read. In Chapter 39, Mrs. Jennings (though she's trying not to hear--right!) thinks she hears the Col. proposing to Elinor.
Then she's set straight.
"Sure you do not mean to persuade me that the Colonel only marries you for the sake of giving ten guineas to Mr. Ferrars!" The deception could not continue after this; and an explanation immediately took place, by which both gained considerable amusement for the moment..."
And think Edward believes Elinor and the Colonel will be married, too, from the way he acts as if he "might hereafter wish the distance between the parsonage and the mansion-house much greater." I think S&S 2 did a great job with this scene. The actors' hand motions alone are priceless!