Through the writing of her diary Maleeka is able to deal more effectively with the many challenges that she faces. In writing the diary she adopts the persona of Aleekma—an anagram of Maleeka—a slave living in squalid conditions below deck on a slave ship.
No matter how bad the conditions are, Aleekma always manages to stay focused and positive. She does this primarily by fixating upon a handsome slave called Kinjali, who keeps a constant eye on her. Kinjali is the alter ego of Caleb, a fellow student of Maleeka's at school, and one of the few people who accepts her despite her dark skin.
For Maleeka, then, writing a diary is a means of escape from all the many problems that she encounters in her life, especially at school. It allows her to find a place where she can be who she really is—beautiful and smart—far from Char and her friends, who constantly put Maleeka down and make her feel worthless. Ironically, it is only by adopting a persona that Maleeka is able to become who she really is, as there's simply no way that she's able to express herself at school, surrounded as she is by so much hostility and incomprehension.