The books first came out in 1992,[1] when Sachar's daughter was four years old, which is why Marvin Redpost has a four-year-old sister.
Marvin Redpost: A young boy and the eponymous character of the series.
He lives in a family of five and often hits the 'red post' on his gate when he leaves or comes back home.
She has blonde hair, with one ponytail sticking out of the side rather than the back, which has some boys to find her 'weird'.
She leaves Marvin to take care of her dog when she goes on vacation, which shows she has more trust on him than other students.