In chapters 11 and 12 of To Kill A Mockingbird, Scout and Jem's understanding of their world expands, and they begin to see beneath the external appearances of people. Individuals in their lives reveal hidden depths. The children begin to be able to see adults they know as three dimensional, not merely cardboard cutout figures that they can easily slot into a category or stereotype.

The first example of this comes in chapter 11. Initially, they understand Mrs. Dubose as merely a witch figure. She sits on her porch a few houses down and does little but insult the children as worthless. She also attacks Atticus to them with verbal brutality for defending Tom Robinson. However, Atticus doesn't hate her for this. He wants the children to see she has greater depths. After Jem knocks the head off her flowers in response to her insults, Atticus makes the children read to Mrs. Dubose. They then learn that she is kicking a morphine addiction before she dies and is a woman of great courage.

In chapter 12, the children learn that Calpurnia is not all that she seems when she takes them to her First Purchase Church. There, they hear her speak in Black dialect and watch her interact with others as a respected member of her community. They also realize how poor the Black community is, and yet how it rallies to help support the family of Tom Robinson.

All of this supports the book's theme that people are more than their surface appearances suggest.

(I have edited your question since only one query is allowed per eNotes post.)

Chapter 11.  

• The children eventually discover that Mrs. Dubose's anger and crankiness comes primarily due to her addiction to morphine.
• Jem finds that he has not killed Mrs. Dubose's prize camellias: He has only damaged them, and Mrs. Dubose leaves him one as a remembrance just before she dies.
• Atticus admits that "I certainly am" a nigger-lover. "I do my best to love everybody..."
• Atticus explains to Jem his reason for making him read to Mrs. Dubose: He wants to show his son that "what real courage is, instead of getting the idea that courage is a man with a gun in his hand." In Atticus's mind, it takes much more courage to face her addiction and impending death than to shoot a defenseless mad dog.

Chapter 12.

• The children see a new side of Calpurnia--how she is respected by the congregation of her church and how she speaks quite differently around her black friends.
• Jem and Scout see both the differences and similarities found at First Purchase Church. The church and congregation are poorer than the white Methodist church, but Reverend Sykes' sermon is not that different from the ones heard in their own church.
• Jem and Scout find that "This church has no better friend than your daddy."
• Jem and Scout find out a little more about the upcoming Tom Robinson trial, and how "Bob Ewell accused him of rapin' his girl."
• The children discover that Cal has learned to read from Miss Buford; that she has grown up at Finch's Landing; that the book she has learned to read from was given to her by Atticus's father; and that Cal is older than Atticus.