Mrs. Turpin’s stereotypes of class and race demonstrate her ignorance.

Mrs. Turpin is obsessed with classes of people.  She considers colored people at “the bottom of the heap,” followed by what she refers to as white trash.  She sees herself at the top, among the “home-and-land owners.”

Mrs. Turpin’s racist and classist opinions are pretty obvious based on her descriptions of people, like “trashy” and “nigger.”  The worst part about it is that these are not insults with her.  They are simply the way she looks at the world.  People are what they are.

If it's one thing I am," Mrs. Turpin said with feeling, "It's grateful. When I think who all I could have been besides myself and what all I got, a little of everything, and a good disposition besides…

This is when Mary Grace hits her with the book, because she is fed up with Mrs. Turpin's shallow platitudes.

Despite her feelings of superiority, Mrs. Turpin is not a better person.  She realizes this when Mary Grace hits her with the book.  She just has a high opinion of herself and a low opinion of others, but in reality in the sight of God she is a lesser person.