In this chapter, we get to actually meet the Mr John Knightleys after having heard quite a lot about them. As a card-carrying founding member of the Mr John Knightley Fan Club, I'm happy to say that the ON describes him as "tall, gentleman-like", so we're safe to assume that he is pleasant to look at.

Isabella, for her part, is described as a "pretty, elegant little woman" -- the opposite of Emma, whom we are given to think of as tall -- and "delicate" in health, and therefore probably pale compared with the "blooming", "picture of health" (Mrs Weston's words) Emma. However, she can't be _that_ delicate, given that she has produced 5 children in 7 years, and we can probably expect( given Emma's conversation with Harriet in Chapt 10 assuming an even greater abundance of little Knightleys in the future) that, being a "worshipping" wife (says the ON) of a husband with "strong domestic habits" (Emma's inner thoughts), and still quite young, that she will have more of them.