A good thesis statement describing Pearl in the Scarlet Letter would be stating that Pearl is a symbol of the love, lust, sacrifice, guilt, and shame that Hester felt, and hence is an extension of Hester's own self. The reason why this would be a good statement is because Pearl's reactions and behavior are proportional to the moment of the story in which there is the most suspense and energy. She was a child with a strange behavior which her mother attributed at the fact that she was a child of sin. Yet, we also know that Pearl developed her behavior as a result of isolation and perhaps also because she in fact has the "sinful residue" of her mother's mistake. The way she made Hester suffer and the lack of tenderness often seen in her are also punishments that Hester feels are well-deserved. So there is no doubt that Pearl is a symbol of all the negative and the little positive in Hester's life.