I didn't mean it seriously that Elinor and LM were alike. I was being sarcastic, but it didn't work :-/

What I meant was that if we were to judge Elinor *only* on the basis of her behaviour at parties, we wouldn't come up with much.
You yourself have quoted incidents involving situations which are otherwise.

So, I will stop beating round the bush, and say boldly that IMO JA didn't understand this character very well.
I have a strong feeling that JA knew one such lady in real life and met her at parties, but didn't know anything about her *other* life. That's why, till now at least, we don't get any account of that.

Also I get a distict feeling that JA didn't like children very much, at least not when they behaved *naturally*, which she calls *spoilt* (I never thought romping around and hanging around their mother was 'spoilt' - guests or no guests).