Character Analysis
Belle Watling, the Atlanta town bad woman (a.k.a. prostitute), is treated in many ways as Scarlett's double. Like Scarlett, Belle is a successful businesswoman—and like Scarlett, her success is seen as scandalous and makes her a social outcast. Like Scarlett, too, Belle sleeps with Rhett. When Scarlett comes to town in order to try to become Rhett's mistress, she thinks to herself:
She wanted to feel superior and virtuous about Belle but she could not. If her plans went well, she might be on the same footing with Belle and supported by the same man. (33.36)
The parallel between Scarlett and Belle functions as a kind of moral lesson, as well as being a sign of the upheaval in social life caused by the war. Everything has changed, and even the distinctions between good women and bad women have been blown away.
But the parallel also serves to insist that some truths, or some social orders, aren't gone. Belle herself is "scandalized" (46.47) when Melly suggests that the other woman should come into her house. Belle is like the slaves who refuse to be freed; she enthusiastically endorses the social order that spits on her. That endorsement is meant to show that the social order is virtuous, that even those who are disadvantaged agree that the disadvantage is necessary and good.
Belle is a way to underline that while Scarlett may have fallen (into work) she hasn't fallen that far (into being a bad woman). She is both a dangerous possibility for Scarlett and a reassurance that things haven't quite come to that point. Like the enslaved characters, she is treated less as a real person and more as a convenient way to tell us about the important, richer people on whom the novel focuses. If you think that Mammy or Belle might be more interesting or better people to build a story on—well, you're out of luck.
Timeline