Alice Through the Looking Glass

Tui T. Sutherland & Kari Sutherland are sisters and best friends, and if you can't tell by looking at them which one is older, Tui certainly isn't going to tell you. They grew up in South America, traveling a lot and moving several times (and they're still only about 80 percent certain that their parents weren't secret agents). Kari now lives in New Jersey, while Tui lives in Boston, but they use every excuse they can to see each other (like, say, writing a book together).