Carrie is a "fallen woman" who achieves a remarkable success in the big city. This was what the publisher's wife and the general American public disliked about Dreiser's novel. They did not object to the fact that Carrie lived with two men out of wedlock. What bothered them was that this sinful behavior didn't lead to the kind of tragic end they were accustomed to reading. If Carrie had gone from being a "kept woman" to being a prostitute, and then to being an alcoholic, and finally a suicide, the public might have been pleased with the novel and it might have received good reviews. Instead of following a downward path as a just reward for her dereliction, Carrie becomes a chorus girl, then an actress, and eventually a star. At the end she seems to have a chance of marrying into a higher social class and attaining genuine self-realization. Whereas her first lover, Drouet, never gets anywhere, and her second lover, Hurstwood, becomes a forlorn panhandler, a "fallen man," and finally a suicide, Carrie achieves fairly impressive success for a farm girl with no education. Dreiser, one of the greatest American writers, very pointedly does not judge her but treats her with the fullest sympathy.
In Theodore Dreiser's novel "Sister Carrie," Carrie can be seen as a fallen woman.
Given that Dreiser was a Naturalist, Dreiser's writings were based on the characteristics typical of the Naturalist movement. Naturalist writers believed that nature was stronger than mankind. Through this, mankind had no free will and could never overcome the powers of nature. (Nature was typically personified to show the supremacy of nature over mankind.) Based upon this, no matter what mankind, in this case Carrie, did, nature always had a plan for the character which would always overpower any plans the character had him/herself.
Carrie, therefore, is a fallen woman based upon the fact that she (through the beliefs of the Naturalist) will always fall in any circumstance in life. Regardless of the measures she takes to survive (leaving home, taking a job in the to help stabilize her financially, relationships which benefit her), she will assuredly fall. This is solely based upon the fact that nature is simply more powerful.