Girl with sickle cell disease had a wish to be on a billboard. She and her twin now smile at passing cars in Md. December 8, 2021 by Leo “I want to be a model,” said Abi, 4, who was granted her dream as part of Make-A-Wish. Source: Girl with sickle cell disease had a wish to be on a billboard. She and her twin now smile at passing cars in Md. Very cool.