Cateau De Leeuw, born to a Dutch-American family in Ohio, loved art from childhood. She and her older sister Adèle worked together to produce their own magazine: Adèle wrote the poetry and short stories, and Cateau provided the illustrations. As children, they travelled widely through South America, Europe, Africa, and the Far East. They were fascinated by their Dutch heritage, and The Netherlands and the Dutch East Indies would later appear as backdrops in their work. Cateau studied at the Metropolitan Art School, the Art Students' League of New York, and in Paris. She then became a professional portrait painter, and eventually had her own studios in Paris, New York, and Plainfield, New Jersey (where Adèle lived). During the Great Depression, she took up illustrating to supplement her income. She was soon illustrating her sister's books, and eventually drew for her own books and for travel magazines. Their collaborations including Mickey the Monkey (1952) and The Expandable Browns (1955). Both sisters lectured extensively at women's groups, art associations, and libraries.