How does Fanny Price relate to social class?

Fanny Price was described even by Austen's family and friends as insipid and timid. But is that all that Fanny Price is? Is Fanny Price's role simply to illustrate a morality tale in which being true to one's values leads to happiness? Fanny is a lower social-economic class girl from a struggling working class family. Her rearing and education are undertaken by her upper class relatives who are of the nobility. She is instructed in where her privileges end and in what her obligations are by her domineering, meddlesome middle class aunt. Fanny's character traits are molded by class demands and barriers at every stage of her life. Does Fanny keep strictly to her moral and religious values because she has an inner trait that compels her to do so or does she because her class position forbids her the privilege to do otherwise, as is suggested by Tara Isabella Burton in "In Defense of Fanny Price" (The Paris Review)?
If it can be argued that Fanny's indoctrination in the limits, barriers and demands of her social class shape her "gentle" though timid personality—and it certainly can so be argued when Mrs. Norris' daily interactions with her, and the Bertram's silence, are analyzed—then it can also be argued that Austen did not intend Fanny's role to be that of illustrating the rewards of holding to moral values. Rather Austen may have intended Fanny to illustrate the constraining inequality and ostracization of socioeconomic class barriers that foster privilege for wealth and power for the upper classes and that exact rigid adherence to codes and morals for the unprivileged lower classes.
This aspect of Fanny's characterization is illustrated when she is contrasted to Mary Crawford for whom wealth, power and connections allow her to brush aside moral breaches. For Mary, "right" is what her wealth and powerful class position can smooth over, while for Fanny, "right" is strict adherence to the demands made upon her by virtue of her powerless class.
How does this socioeconomic class analysis effect the analysis of Fanny's character? When we consider that Fanny actually resisted the influences of wealth and power and, in her own gentle and timid way, spoke out against wrong moral choices, we can say that Fanny absorbed the determination and strength of convictions that usually only upper class people had the privilege to express. Fanny doesn't give in like a servant or village peasant might have to do; she resists.
Fanny may be timid and, perhaps to some, insipid, but she has nonetheless absorbed some of the dynamic of determined assertiveness that is part of the privilege of the upper classes.