Sisters Maryanne and Shayle Bester have cooked up nine picture books together, all published by Jacana. Some of these feature Gaps, the Nguni calf, and his extended family. Others, like Three Friends and a Taxi, are light-hearted contemporary tales. Three Friends and a Taxi was a winner of the 2004 Sappi Isiqalo Book Competition and The Cool Nguni was one of the winners of the Exclusive Books IBBY SA Awards. The sisters grew up on a Free State farm but now live in Gauteng with an assortment of family and animals. All their stories draw on their deep affection for the people, places and eccentricities of Africa.

Their previous works include The Cool Nguni, Why Dog is Afraid of Storms, I Know That!, Three Friends and a Taxi, The Long Trousers, The Missing Ball and Mealies and Beans. Three Friends and a Taxi was a winner of the 2004 Sappi Isiqalo Book Competition, which encourages South African authors and illustrators to develop material with a local idiom to promote reading, writing and access to books for all.

In 2007 The Cool Nguni by Maryanne and Shayle Bester was one of the winners of the Exclusive Books IBBY SA Awards for children's book writers and illustrators. IBBY Award certificate to Xolisa Guzula for Iinkonde eMnyango her isXhosa translation of The Elders at the Door by the Bester Sisters..

Maryanne and Shayle Bester are sisters who grew up on a Free State farm, where their father farmed cattle and sheep. They both graduated from the University of Natal in Pietermaritzburg, Shayle majoring in Fine Arts and Maryanne in Dramatic Arts. Together they run a company as decorative painters and illustrators, specialising in children's art.