Now Emma agrees with Mr Knightley's earlier assessment on Harriet's status! re end of chap 47 --

'Mr. Knightley and Harriet Smith! It was an union to distance every wonder of the kind. The attachment of Frank Churchill and Jane Fairfax became common-place, threadbare, stale in the comparison, exciting no surprise, presenting no disparity, affording nothing to be said or thought. Mr. Knightley and Harriet Smith! Such an elevation on her side! Such a debasement on his! It was horrible to Emma to think how it must sink him in the general opinion, to foresee the smiles, the sneers, the merriment it would prompt at his expense; the mortification and disdain of his brother, the thousand inconveniences to himself.'