When is aunt Alexandra prejudiced?

Aunt Alexandra is a very prejudice woman. She does not tolerate Calpurnia being the only motherly figure for scout. She shows Calpurnia little respect because she believes Cal is of "lower class".

She also judges others because of their family name. Atticus even jokes with her asking if she would judge their family too. By knowing your name she instinctively "knows" how you are suppose to act.