If any thing could be more, where all was most, she was more reserved on the subject of Weymouth and the Dixons than any thing. She seemed bent on giving no real insight into Mr. Dixon's character, or her own value for his company, or opinion of the suitableness of the match. It was all general approbation and smoothness; nothing delineated or distinguished. (Chapter 20)

I just made up the questions based on what is in this paragraph (above) just as you surmised; it is not kind of you to point it out but I readily confess I do not compare with JA—I am positive she would have written less blatant questions. However, she did not and it does not really matter because Emma gives us the subjects of her questions and apparently Jane did not want to answer them to Emma’s satisfaction. I don’t find Jane was remiss as a guest in conservation or otherwise. All I know for sure is she did not satisfy Emma’s curiosity about people Jane has no obligation to enlighten her about. IMO what has Emma in a snit is not that Jane was remiss as a guest but that she could not get the real insights she wanted from Jane about Weymouth, the Dixons and Frank Churchill. Jane did contribute to conservation and if she does not have to be a witty conversationalist as you say then participation should be enough. Mr. Knightley saw nothing wrong in Jane’s behavior—Chapter 21.