Photographic evidence for Karen's thumb sucking and handedness experiment
Lauren has a Princess diary she's been writing in this summer. I figured it was a good way for her to practice writing without it seeming like an assignment. Of course, since Lindsay has to do everything Lauren does, she is "writing" in a book also.
Karen, Lindsay's handedness would appear not to support your theory. She always colors with her right hand, and yet she only sucks her left thumb. Alec is left handed, and I am right handed. Lauren is right handed.