] Their estate was large, and their residence was at Norland Park, in the centre of their property, where for many generations, they had lived in so respectable a manner as to engage the general good opinion of their surrounding acquaintance.

] There are those wonderfully ambiguous words 'respectable' and 'general good opinion' nestled in there. If it is, indeed, the duty of a family, first and foremost, to be thought well-of by one's neighbours, well, the Dashwoods seem to have succeeded thus far at the opening of the novel. However, JA doesn't define the nature of this respectability, nor whether the Dashwoods are deserving of their acquaintances' good opinion - or conversely, whether the 'general good opinion' of the neighbours is worth having.

Actually, I took this sentence at face value. The Dashwoods live in the country, not the city, and have done so for several generations. The area around Norland sounds like the kind of place where people would not only know you, but probably would have known your parents and possibly your grandparents, as well. If you've ever lived in a small town, it's amazing how well people know each other's so-called secrets! I suspect that the Dashwoods' neighbours would have known whatever they were up to (at least locally) and whether they deserved a good reputation or not. On the other hand, I agree that the local neighbours might not really be aware of what was happening to the Dashwood ladies after they moved so far away.