Anderson began her career as a freelance journalist and worked at The Philadelphia Inquirer in the early years of her career. During this time, Anderson also began to write children’s and young adult novels. Despite receiving rejection letters, Anderson released her first children’s novel, Ndito Runs, in 1996, based on Kenyan Olympic marathon runners who ran to and from school each day. Later that year, she had her story Turkey Pox published. This story was inspired by her daughter, Meredith, who broke out with chicken pox on Thanksgiving. In 1998, Anderson published No Time For Mother’s Day, featuring the same characters. She received the Margaret A. Edwards Award from the American Library Association in 2010 for her contribution to young adult literature.