if you look at that passage with slightly different emphasis:

James and Isabella led the way; and so well satisfied was the latter with her lot, so contentedly was she endeavouring to ensure a pleasant walk to him who brought the double recommendation of being her brother’s friend, and her friend’s brother, so pure and uncoquettish were her feelings, that, though they overtook and passed the two offending young men in Milsom Street, she was so far from seeking to attract their notice, that she looked back at them only three times. (Ch. 7)