Characterize Sophia from The Color Purple. What effect does she have on Celie?

In The Color Purple, Sophia is a bold character who stands up for herself when she feels wronged.  She loves Harpo, but she refuses to be abused by him when they get into disagreements.  Similarly, when she is insulted by the mayor's wife while in town, she speaks up for herself.  But even though Sophia stands up for herself, she does not necessarily think through the best ways to handle these difficult situations.  She ends up splitting up with Harpo and being jailed for back-talking to the mayor's wife because of her harsh demeanor.  From Sophia's example, Celie learns that she must also speak up for herself, but that she must be smarter in her resistance.