I was a little confused by JA's comment in letter 63: "Miss Hook is a well-behaved, genteelish woman; Mrs. Drew well behaved, without being at all genteel."

I always thought that genteel *meant* well-behaved, or to conform to accepted standards of behaviour, so I looked it up at Merriam-Webster online (which of course is not a contemporary source), and found this:

1 a : having an aristocratic quality or flavor : stylish b : of or relating to the gentry or upper class c : elegant or graceful in manner, appearance, or shape d : free from vulgarity or rudeness : polite
2 a : maintaining or striving to maintain the appearance of superior or middle-class social status or respectability b (1) : marked by false delicacy, prudery, or affectation (2) : conventionally or insipidly pretty

I suppose definition 1a) would work - you might be well-behaved without having an aristocratic flavour.