I'm writing a story about two sisters, and I need a title?

Hey. As a fellow author, I find that sometimes you have to wait to finish the story, and then find a title within. I mean- let's say one day your novel becomes famous and you're on Oprah or Larry King. One of your interviewers asks you what was your inspiration for the title. You might lie and tell them something else, but deep down you know you got your title from a stranger on Yahoo Answers. LOL. And I'm really sorry, but I can't think of any titles.