Looking for title of book !!

[ANGELeyez20027]

I read about half this book and forgot the title and author of it and would really like to finish it ! The main character is a girl I would say in her late teens or early twenties and she has been extremely sheltered up unitl now, her father had made a harmless and safe home for them and had never wanted them to leave it . However, her brother is the first to leave, and she is forced to go look for him when someone in the family gets sick. She stil dresses as if it were the 1950\\\'s and starts to learn that there is alot going on in the world she didnt know about. Also there is some kind of background story going on also, with an actress and an actor which I believe in the end of the story end up being her parents.