The romantic rumor of Mr. Knightley and Jane Fairfax had some of the momentum removed from it in Ch 33 - Mr. Knightley himself speaking:

"....but not even Jane Fairfax is perfect. She has a fault. She has not the open temper which a man would wish for in a wife...."

"....She is reserved, more reserved, I think, than she used to be: And I love an open temper...."

And from Ch 29:

"....The party did not break up without Emma's being positively secured for the two first dances by the hero of the evening, nor without her overhearing Mr. Weston whisper to his wife, "He has asked her, my dear. That's right. I knew he would!"

The Westons are hoping to make Emma and Frank Churchill a number.