The confrontation between Elizabeth and Lady Catherine underscores Elizabeth's ability to hold her own with those aristocrats whose pride will make them prejudiced against her when she becomes Darcy's wife. From the beginning of the novel, Elizabeth was shown to be capable of resisting others' wills and clearly articulating her beliefs. However, Elizabeth's maturation process has given her a deeper understanding of herself and of others, and as a result she is able to deal with adversity in a much calmer, less confrontational manner. Since she had her self-revelation, Elizabeth has controlled potentially volatile situations with complete confidence. She deflated Miss Bingley's attempts to provoke her at Pemberley, put Wickham in his place after he married Lydia, and now easily routs her most challenging adversary, Lady Catherine De Bourgh.
The ironic result of Lady Catherine's visit is to insure the marriage between Darcy and Elizabeth. Lady Catherine came in order to prevent it, but when Darcy hears the manner in which Elizabeth answered her, he realizes that Elizabeth's feelings must have changed in some degree. If she had felt as she did when she told him that he was "the last man in the world whom I could ever be prevailed on to marry," she certainly would not have refused to say she would never accept a proposal from him. Although Elizabeth and Darcy probably would have eventually made their feelings known to each other without Lady Catherine's meddling, her interference helps to expedite the process.
