There is still more

The final reference to Richardson (for now anyway) comes at the very end of the chapter wherein Austen discusses whether or not Catherine dreamed of Henry that night. She does not answer her own question because she only introduced the subject to geta dig in at "a celebrated writer":

... for if it is true, as a celebrated writer has maintained, that no young lady can be justified in falling in love before the gentleman's love is declared, it must be very improper that a young lady should dream of a gentleman before the gentleman is known to have dreamt of her.

The celebrated writer is Richardson. I know this because a footnote in my edition tells me that Richardson expressed this very belief in a letter to The Rambler (#97).

I can't help but notice that while Austen mocks Richardson's attitude here, she is not so far away from it as we might conclude. Sense and Sensibility is very much concerned with questions of when it is prudent to, or proper to, let yourself fall in love and while the answer Austen gives there is much more detailed and nuanced that Richardson's, it isn't that far from his in its general thrust.