At the beginning of chapter five it states that she was named Pearl because she was "of great price-purchased with all she had,-her mother's only treasure!" So, Pearl's name is symbolic of the price that Hester had to pay in order to bear her. She sacrificed her reputation, her life, and any chance of a real happiness in that town. She paid dearly for Pearl to enter into the world.
Also symbolic is the proess by which pearls are created. They start as a grain of sand in an oyster, but through years of pressure and trying friction, eventually are transformed into pearls. In the novel, Pearl was the result of great trial, great pressure, and great friction; her parents suffer greatly, and what they have to show for it is a beautiful child-Pearl.
I hope that helps a bit!
In The Scarlet Letter by Nathaniel Hawthorne, Pearl is the daughter of Hester Prynne and a product of Hester's adulterous relationship with a minister, the Reverend Arthur Dimmesdale. Hester Prynne was married to Roger Chillingworth, and thought herself a widow at the time of the adulterous relationship. While Hester is jailed and pilloried for adultery, she is determined to keep Pearl and create a life with her.
The name Pearl is derived from the Bible, specifically Matthew 13:45-46, which is a parable comparing the kingdom of Heaven to a merchant:
... who, when he had found one pearl of great price, went and sold all that he had and bought it.
This suggests that Hester will sacrifice everything for Pearl, who is the most important thing in her life. It implies that for Hester, Pearl is more important than worldly goods or reputation. In the comparison of Pearl to Heaven, it emphasizes a model of Christianity in which a mother's love for her child is a form of Christian piety, and that the sin of adultery counts for less in the eyes of God than Hester's devotion to Pearl.