The major event of the Meryton Ball being Darcy's remark about Elizabeth's features placed him in her bad books. She was resolved to think ill of him and Wickham's timely arrival and his woven tales of injustice at the hands of the Darcys only fueled her prejudice. Wickham's tales merely gave her more 'insight' into who she wanted to believe Darcy is; a blackguard. She was quick to judge him based on one comment.
To her, there is nothing good about him and she wrongly sketched his character to which Darcy ended up challenging her about
Elizabeth hadn't conversated with Darcy much and when she did he was rude.
When she heard Wickham's "story" she assumed him to be misfortunate yet a pure hardworking soul.
Ironic cause it switches towards the end, Wickham shows how truly wicked he is, whilst Darcy shows how passionately in love with Elizabeth he is. As well as, how his actions towards Wickham were what he deserved. However, we're just talking about the early portion of the novel.
