Dear 100 Hour Board,
To practice French, I got a translated copy of Sense and Sensibility. In this version, Elinor, Marianne, and their mother all use vous with each other. Why would family members address each other formally? The ISBN is 2-264-02381-3 and it was translated by Jean Privat.
Dear French Learner,
I contacted my newest-to-the-family aunt (she recently married my forever bachelor uncle) who is from France and lived there up until a few years ago. She told me that it was very common to use formal language when addressing family in the time Austen's novels are set (1800s), though most people now use informal language with close family members. This formal language was especially common in high society! This means that most translations of Austen's novels into the French are going to use this formal language, even newer translations, as a way to show what time period the novels were set in (just like we don't regularly modernize Austen, Shakespeare, and other writers with era-specific language). Here's an example Katya gave me of another French translation of an Austen novel that uses "vous" between family members.
-Yog in Neverland