This may be because she feels adrenaline from the thought of getting caught by Darcy.
On seeing the grounds of Pemberley House, Elizabeth describes the gardens as “beautiful”, and the house as “handsome”. This praise of the house is likely to reflect her sub-conscious feelings towards Darcy, though she does not yet realize it.
We also know that in Elizabeth’s first few thoughts, she anticipates what it would be like to be mistress of the house, and to be acquainted with a family of such a high status. However in “a lucky recollection”, she quickly forgets those dreams. The word lucky in that line surely implies that she is denying the desire she feels to own Pemberley if it entails a marriage between herself and Darcy.
Later in the chapter, Mrs. Reynolds, Darcy’s housekeeper, shows Lizzy and the Gardiner's around the house. Elizabeth is astonished when the housekeeper says she’s
“never had a cross word from him in my life”,
And that infact all of his servants think very highly of him. This is quite the opposite of what Elizabeth had expected to hear, as she had believed up until then that Mr. Darcy was a bad tempered man. The housekeeper continues to sing Darcy’s praises as a master and tells of his generosity towards his sister, much to Lizzy's disbelief After such a good description of the man she had grown to hate, she finds herself thinking only of him, undistracted by the magnificent house and furnishings.
This is where I believe Elizabeth’s opinion begins to change, as she realizes that her judgment of character had been contrary to the truth.
As the tour of the house draws to an end, they move on to take a tour of the grounds with the gardener. It is to all of Lizzy’s regret and embarrassment to find Mr Darcy walking directly towards the party, presumably having of returned from his trip early.
However Elizabeth is very surprised at the difference in his manners compared to the last time they met,
“Never in her life had she seen his manners so little dignified”
Lizzy finds herself to met his eyes, or reply to his enquiries with any ease.
Though after Mr Darcy’s leaves the party, she feels
“over-powered by shame and vexation,” and felt that “Her coming there was the most unfortunate, most ill-judged thing in the world.”
This amount of regret and embarrassment suggests that she does infact seek highly of his opinion. Elizabeth also wonders what his thoughts wereon their meeting, indicating that she also cares about his feelings towards her.
When the party meet with Darcy for the second time, Lizzy is simply astonished when Mr Darcy invites herself, Mr. and Mrs. Gardiner to meet with his friends and family at Pemberly the following day,
“The surprise of such an application was great indeed; it was too great for her to know in what manner she acceded to it.”
Elizabeth and the Gardiners then departed from Pemberly house, after giving their many thanks to Darcy. Mr. and Mrs. Gardiner begin to praise Darcy, commenting on his manners and generosity. Elizabeth admits that she has grown to like him, and claims that
“She had never seen him so pleasant,”
However on her aunts comparison to Wickham, she remembers how Darcy treated him, and doing so sees Darcy less aimable than she had thought.
