I believe the quote you may be looking for is the one below:
Well, coming out of the courthouse that night Miss Gates was—she was goin‘ down the steps in front of us, you musta not seen her—she was talking with Miss Stephanie Crawford. I heard her say it’s time somebody taught ’em a lesson, they were gettin‘ way above themselves, an’ the next thing they think they can do is marry us. Jem, how can you hate Hitler so bad an‘ then turn around and be ugly about folks right at home—
In the above quote, Scout asks Jem why Miss Gates treats two groups of people differently. During a Current Events class, Miss Gates teaches the children that Hitler was wrong to persecute the Jews. She explains that Germany and the United States differed in that the latter was a democracy, while the former was a dictatorship.
When Miss Gates asks the class what "democracy" means, Scout answers. Her answer also demonstrates that she believes in equality:
"Equal rights for all, special privileges for none," I quoted.
Because Scout believes that everyone is equal, she is especially troubled when she hears Miss Gates denigrating members of the African American community in Maycomb. Of course, Scout's values are the product of her upbringing, and her sense of fairness has been carefully honed under Atticus's tutelage.