The wonderful link in Cathy Allen's post below mentions something that had never occurred to me before, and I'd love to hear the opinions of the board. Within this essay, the author claims that Lady Catherine admires Lizzy. (I don't want to quote it here since the link does have some spoilers.) As I thought about it, I noticed that

1) Lizzy is the only person we see have a real conversation with Lady C. While Lady C certainly talks a lot, and Mr. Collins is obsequious, I cannot think of any place where JA shows us any real interaction besides Lizzy.

2) Lady C actually invites Elizabeth to stay a full additional month with the Collins. (what presumption!) There can be no occasion for your going so soon. Mrs. Bennet could certainly spare you for another fortnight.... And if you will stay another month complete, it will be in my power to take one of you as far as London.