Where did Princess Leia's dual-mounted hair buns come from? George Lucas wrote:
In the 1977 film, I was working very hard to create something different that wasn’t fashion, so I went with a kind of Southwestern Pancho Villa woman revolutionary look, which is what that is. The buns are basically from turn-of-the-century Mexico. Then it took such hits and became such a thing.
The above right image shows a woman sometimes said to be one of Pancho Villa's wives as well as the inspiration for Leia's hairstyle. But Michael Heilemann, a Star Wars historian, is skeptical:
But once you sever the connection between the photo and Lucas’ Pancho Villa statement and take a closer look at how the hair is actually done, it’s quite obvious that the likelihood of that connection being slim. This isn’t to say that this hairstyle didn’t originate where Lucas says it did. It may have; though I have been unable to find any evidence to support that statement, and the alternatives simply sound much more likely, given Lucas’s use of movies and comics as his primary sources of influence.
Heilemann then goes on to describe other possible sources from film, television and comic books.
Plus it's obvious that Lucas himself has been making it up as he goes along.. so why not let other people have fun too?