Hester Prynne is consistent in her rebelliousness throughout the novel. However, there are aspects of her rebellious nature that had to completely tone down from their original fire and energy. This is because, by chapter 5, "Hester at her Needle," it is revealed that Hester has grown over-saturated from public scorn. She suffers from the mistreatment of the people that she often tries to help and continues to be the moral channel of the masses.
...for the accumulating days and added years would pile up their misery upon the heap of shame. Throughout them all, giving up her individuality, she would become the general symbol at which the preacher and moralist might point, and in which they might vivify and embody their images of woman's frailty and sinful passion.
Those whom she makes garments for also take digs at her. She cannot even get a moment of respite by going to church, like any other Christian, because she would undoubtedly become the topic of a sermon. She is a public pariah. As such, she is also the scapegoat of the people who channel their nasty thoughts and emotions, that they keep held up inside, through their hatred of her.
Hence, Hester would live with her scarlet letter, while altruistically serving others, with neither scorn nor anger toward them. She simply became a self-appointed sister of the people, a nurse, a helper; someone who, later on, the villagers would identify with the "A" of "able".
Yet, other chapters will show stamps in Hester's life that still prove that there is fire within her.
In chapter 8, "The Elf Child and the Minister", Hester boldly demands that Dimmesdale speaks on her behalf so that the magistrates do not take Pearl away from her.
God gave her into my keeping!" repeated Hester Prynne, raising her voice almost to a shriek. "I will not give her up!" [...]she turned to the young clergyman, Mr. Dimmesdale, at whom, up to this moment, she had seemed hardly so much as once to direct her eyes. "Speak thou for me!" cried she...
In this chapter, she also tells Mistress Hibbins- the town's witch- that she would be more than glad to go into the forest to conduct what we could assume are heretic acts, had the magistrate taken Pearl away from her.
Had they taken her from me, I would willingly have gone with thee into the forest, and signed my name in the Black Man's book too, and that with mine own blood!
Hester also shows up in the forest to speak to Dimmesdale, and plans their escape from the village. She tells him that there is no use living up to a lie in Boston, and that there is more to life than this fake priesthood image that he tries to portray.
Finally, Hester is brave enough to book the trip for her, Pearl, and Dimmesdale directly with the sully sailors that visit the village and are considered to be rough and rowdy. Hawthorne says that Hester has essentially "had it" with the social machinations of who speaks with whom, and she knows no elitism or social difference.
The most rebellious act committed by Hester is definitely returning to the village after the debacle is over. Not only does she come back, but she also is happy to live alone, still wearing the scarlet letter on her bosom.
It is clear that the letter has helped to forge her an identity where she feels stronger and more self-possessed as a woman. Notice that Hester's story is NOT a love story. It is a story of sin, loss, and redemption. She has been her own judge and jury. She owns herself.