"Lydia’s last letter she prepared [me] for such a step. She had known, it seems, of their being in love with each other many weeks” (276).
After the Bennets learn about Lydia running away with Mr. Wickham, Kitty triumphantly admits to knowing of their relationship first after Lydia sent her a letter telling her
“[Kitty is] weak-spirited, irritable, and completely under Lydia’s guidance” (203).
“[Kitty's] improvement was great. She was not of so ungovernable a temper as Lydia, and removed from the influence of Lydia’s example, she became, by proper attention and management, less irritable, less ignorant, and less insipid.” (367).