Lydia and Kitty, Charlotte and Lizzy: best of friends
Both relationships change dramatically by the end of the book/movie, the pairs are separated and only maintain contact through family relationships. It’s marriage that will separate them; Lydia’s marriage to Wickham and Charlotte’s to Collins. The former everyone with the exception of Kitty and her mother disapprove, the latter everyone with the exception of Lizzy and her mother approve.
I was struck by the similarity of these scenes at the Netherfield Ball; two friends all dressed in white walking together and laughing. You can see the younger two acting at being grown up while probably drunk. Even the hair adornments are similar; Kitty and Lydia have feathers while Charlotte and Lizzy have flowers in their hair.
If you’d like to discuss Austen with me you can book a time
Video from Pride and Prejudice 2005
Audio from You’re On Your Own Kid by Taylor Swift