Pride and Prejudice Volume 3, Chapter 14
About a week after Jane's engagement, Lady Catherine De Bourgh shows up at Longbourn and wants to speak with Elizabeth. She tells Elizabeth that she's heard that Elizabeth and Darcy are engaged, and she's outraged. She lectures Elizabeth on how ill-suited she is to Darcy and how she would ruin him if she married him. Elizabeth listens to the insufferable woman's insults and finally tells her that if Darcy wants to marry her, it's none of Lady De Bourgh's concern and she'll just have to deal with it. Lady De Bourgh insists that Darcy is supposed to marry her daughter, and Elizabeth says that if he doesn't want to marry Miss De Bourgh, he shouldn't have to. When Elizabeth finally admits that she and Darcy are not engaged, Lady De Bourgh tries to make her promise that she'll refuse him even if he asks, but Elizabeth won't do it.
She says, "I am not to be intimidated into anything so wholly unreasonable . . . You have widely mistaken my character, if you think I can be worked on by such persuasions as these. How far your nephew might approve of your interference in his affairs, I cannot tell; but you certainly have no right to concern yourself in mine." Volume 3, Chapter 14, pg. 246
Lady De Bourgh leaves in a huff.