In "Odalie Misses Mass," what is Kate Chopin saying about the South using muckraking? What is she trying to illustrate about the South? How?

Muckraking is considered investigative writing meant to expose social ills or corporate and political corruption. In her short story "Odalie Misses Mass," Kate Chopin exposes some of the social ills of slavery.
When Odalie stops at the cabin of Aunt Pinky, she finds the old slave, "the helpless, shrivelled old negress," alone. Disturbed that Aunt Pinky is alone, Odalie learns that a young slave named Pug has left her to go to church. So, Odalie calls to her waiting mother that she is going to stay with Aunt Pinky and cannot continue on with her to church.
When she resumes her seat, Aunt Pinky repeats "done gone" a few times, suggesting that she is left alone frequently. Then, Aunt Pinky recalls when Odalie's grandfather said he would have to sell Pinky and others because he had hit hard times, but he did not sell Pinky after witnessing how fond Odalie was of her and when Odalie insisted that she did not want fancy things if it meant selling Aunt Pinky. Aunt Pinky also recalls to Odalie the time that she caught her crying because Pinky wanted to marry Hiram, a servant of a certain Mr. Benitou.
Because Odalie went home and cried and broke dishes 

"...an' pesters yo' gran'pap 'tell he bleedge to buy Hi'um f'om de Benitous."

Odalie's grandfather again softens and gives in to his granddaughter, and Pinky gets to marry Hiram. The contrast between the treatment and consideration for his granddaughter and that given his slave exposes the cruelty and disregard for human feelings that slave owners exhibited frequently in the South.