In The Scarlet Letter is Hester Prynne a conformist? If not, why does Hawthorne represent her as nonconformist?

While Hester's relationship to conformity is a complicated one, Hawthorne generally depicts her as a kind of conformist.  The key scene for this reading is in Chapter XVIII, "A Flood of Sunshine," in which Hester throws off the scarlet A she has been ordered to wear by her Puritan community.  In her secret meeting in the forest with Dimmesdale,

she undid the clasp that fastened the scarlet letter, and, taking it from her bosom, threw it to a distance among the withered leaves.  The mystic token alighted on the hither verge of a stream.  With a hand's breadth farther flight it would have fallen into the water, and have given the little brook another woe to carry onward, besides the unintelligible tale which it still kept murmuring about.  But there lay the embroidered letter, glittering like a lost jewel, which some ill-fated wanderer might pick up, and thenceforth be haunted by strange phantoms of guilt, sinking of the heart, and unaccountable misfortune.

As the narrator makes clear, by getting rid of her "mystic token," Hester sheds her "guilt," sinking heart, and "misfortune."  As the text continues, the letter is called a "stigma," whose riddance comes as a relief.  This act is nonconformist on Hester's part, as she repudiates the punishment that the town has required of her.  However, after watching her daughter Pearl play in the wilderness, she decides to put the letter back on:

she advanced to the margin of the brook, took up the scarlet letter, and fastened it again into her bosom.  Hopefully, but a moment ago, as Hester had spoken of drowning it in the deep sea, there was a sense of inevitable doom upon her, as she thus received back this deadly symbol from the hand of fate.

From this scene, we can see that because of the "hand of fate" Hester feels as though she must again "fasten" the letter "into her bosom."  While she gains a brief moment of nonconformist freedom by casting it off, she ultimately decided to wear it again, signaling her conformity to the punishment she receives and the community that sentenced her.  This sentiment reappears at the end of the novel when Hester decides to remain close by the town instead of fleeing.