In Chapters 38 to 43, the chapter that best characterizes Elizabeth's developing change in bias towards Darcy is Chapter 40 in which Elizabeth finally gets a moment alone with Jane to tell her about Darcy's proposal and the letter revealing Wickham's character. It is in this chapter that Elizabeth openly confesses to Jane that, while at first she believed Darcy to be cruel and Wickham to be amiable, she now believes that Mr. Darcy is actually the blameless man. She further states, "There certainly was some great mismanagement in the education of those two young men. One has got all the goodness, and the other all the appearance of it" (Ch. 40).
However, it is not until Chapter 43 in which Elizabeth takes a tour of Pemberley with her Aunt and Uncle Gardiner that her mind becomes even more changed about Darcy. While touring Pemberley, she especially has the opportunity to admire Darcy's taste. For example, she notes that the banks of the river flowing in front of Pemberley House were "neither formal, nor falsely adorned" and that the natural beauty of the grounds had not been "counteracted by an awkward taste" (Ch. 43). She also has the opportunity to admire his taste with respect to the house's furnishings. While the rooms are large and expensively decorated, she also sees that the furnishings are "neither gaudy nor uselessly fine," like at Rosings (Ch. 43). Instead, the furniture is genuinely elegant. Seeing Darcy's taste certainly opens Elizabeth's heart up to better see his character; however, his housekeeper's praise of him best helps her to see Darcy with less bias. She has assumed that Darcy is the type of man who is always grumpy and out of sorts; however, the housekeeper claims that she "never had a cross word from him in [her] life" (Ch. 43). The housekeeper further asserts that, even when she knew Darcy as a boy, he had been the "sweetest-tempered, most generous-hearted, boy in the world" (Ch. 43). The housekeeper even contradicts others' opinion that Darcy is a proud man, saying that he only appears proud because "he does not rattle away like other young men" (Ch. 43).
If hearing his character described by Darcy's housekeeper is not enough to change Elizabeth's mind about Darcy, seeing him person is. Darcy even surprises her by asking to be introduced to her aunt and uncle. She observes that he is surprised to learn that they are some of her working class relations, but instead of turning away as she would have expected, he continues walking the grounds with them, conversing with Mr. Gardiner and inviting him to fish on the estate. He even asks her permission to introduce her to his sister. It is meeting and conversing with Darcy in this way, plus seeing the change in his behavior, that truly makes Elizabeth put an end to her biased opinions of Darcy.