Pearl's role in the novel is subject to much interpretation. Most obviously, to the Puritans she represented sin, the physical proof of human sinfulness and moral frailty. Her presence branded Hester as much as the scarlet letter she wore. However, Pearl (as well as her mother) were not considered to be beyond spiritual redemption. Pearl's remaining with her mother was contingent upon Hester's instilling in her the tenets of the church.
Hester's view of Pearl was complex. Pearl was a reminder of Hester's spiritual downfall, but she was also a reminder of Hester's love and passion for Dimmesdale. Hester takes a secret pride in Pearl, defiantly dressing her in bright colors. When alone in the forest with Dimmesdale, Hester expresses her love and joy in their child.
On another level, Pearl represents salvation for Hester, both physically and spiritually. It is Pearl who keeps Hester "in life," and it is she who keeps Hester from further moral downfall. This idea is expressed when Hester explains why she should be allowed to keep her daughter.
Finally, Pearl represents the triumph of love and goodness over hatred and evil. Through her mother's love and devotion, Pearl grows into a strong young woman who moves on to live a good life in England. She inherits all of Chillingworth's estate, his acknowledgment that she had suffered as the result of his obsessive pursuit of revenge against Pearl's father. Of the novel's four major characters, only Pearl was innocent, and innocence is rewarded in the novel's conclusion.
She was a reminder of her mother's sin. She was a child born from "sin".