Blanche has possible origins from Fontaine (the equivalent of France in Teyvat) though she's not once mentioned it. She runs Mondstadt general goods as a shopkeeper, but outside of that, she's very knowledgeable on all things to do with Mondstadt, including where to get the Best Wine, Food, meet interesting people, socialise, etc. Her personal life is pretty unknown and her personality is too, except from the fact she's very helpful. In fact, she likes to help, making her a sociable person.