Why is there so many French passages? Coby Skretta

There is a lot of French in Jane Eyre for seemingly no reason.  Most of the time Bronte doesn't even offer up a clear translation or strong context clues as to the meaning. 

I think this may be simply because more people spoke French when she wrote this book.  Bronte didn't write this book for high school students in the early 21st century.  She wrote it for the people of England in the mid 19th century.  I'd bet that more people from her originally intended audience had a basic understanding of French than us high school students do today.