The reason why Pearl is more than a handful for her mother Hester in Nathaniel Hawthorne's The Scarlet Letter, is because the character of Pearl is meant to be a literal and philosophical consequence of Hester's actions.
This being said, Pearl is not only the product of the illicit relationship between Hester and Dimmesdale: She is also the source of Hester's "preternatural" punishment for having allowed herself to defend a man who has clearly committed a crime much worse than her own. Dimmesdale deserves no mercy. Yet, for whatever her real reason is, Hester elects to spare him the humiliation and the punishment that he truly deserves.
Since her decision is not necessarily the correct choice to make, she will pay for the consequences of it through Pearl, who is a spiritual extension of Hester. It seems as if Pearl can read her mother's soul. She knows what her mother's weaknesses are, and what makes her mother upset. She manipulates her mother's emotions as if reminding her that, because of her choice of saving Dimmesdale, both Pearl and Hester live a life of pariahs. Pearl is a manifestation of Hester's weaknesses, but her strength of character makes those weaknesses more evident in Hester's eyes.
In not so many words, Pearl was put in this world to make Hester pay for saving Dimmesdale, and for her not to ever forget how this decision basically destroyed life, as she knew it, forever.