Miss Bingley was venting her feelings in criticisms on Elizabeth’s person, behaviour, and dress. But Georgiana would not join her. Her brother’s recommendation was enough to ensure her favour: his judgment could not err, and he had spoken in such terms of Elizabeth as to leave Georgiana without the power of finding her otherwise than lovely and amiable.
– Jane Austen
Pride and Prejudice, Chapter 45. After Elizabeth and her aunt leave Pemberley, Caroline just can’t stop herself making spiteful comments about Elizabeth. But Georgiana refuses to join in, she trusts her brother Fitzwilliam Darcy’s good judgement that Elizabeth is nothing other than "lovely and amiable." The close family bond between Georgiana and her brother is evident here. There is much irony in Caroline criticizing Elizabeth’s behavior, since she herself is guilty of behaving badly.