They owed the restoration of Lydia, her character, every thing, to him. Oh! how heartily did she grieve over every ungracious sensation she had ever encouraged, every saucy speech she had ever directed towards him. For herself she was humbled; but she was proud of him. Proud that in a cause of compassion and honour, he had been able to get the better of himself.
– Jane Austen
Pride and Prejudice, Chapter 52. Elizabeth feels humbled after her aunt Mrs. Gardiner reveals in a letter that it was Darcy who found Lydia and Wickham when they ran off together. He tracked them down at their London love nest. He also paid Wickham the money to facilitate their marriage, but asked that Mr. Gardiner take the credit for it. Elizabeth is proud of Darcy and the "compassion and honour" he showed through his actions and generosity. She also repents her previous dislike of and prejudice that she displayed to him.