Mary Pope Osborne is the author of the New York Times number one bestselling Magic Tree House series as well as co-author of the Magic Tree House Fact Tracker series, along with her husband, Will, and her sister, Natalie Pope Boyce.

Giselle Potter and her sister, Chloe, traveled a lot with their parents' puppet theater. They often had just each other for companionship and therefore became very close. So Potter feels so lucky to have two daughters who are also very close. Watching their relationship, she is reminded of the unique, unmatchable bond of sisters. Potter has illustrated more than thirty children's books, and many of the books she both wrote and illustrated are either about or inspired by sisters.