Why does Alexandra think Atticus should dismiss Calpurnia, and how does Atticus respond to the suggestion in To Kill a Mockingbird?

The subtext behind the
reason that Aunt Alexandra thinksshould dismiss Calpurnia is thatis becoming too friendly with
African-American people and wants to visit Calpurnia at her house. While Aunt Alexandra says
that Scout is too old for Calpurnia, Alexandra's real reason for wanting to get rid of Calpurnia
is that Alexandra thinks Scout is too close to African-Americans through Calpurnia. However,
Atticus immediately rejects this idea and says that Calpurnia is "a faithful member of this
family" and will leave her position only when she wants to. He also says that Calpurnia has
been harder onand Scout than a real mother would have been and that Calpurnia has not been
indulgent towards the children. Atticus feels that Calpurnia has a good sense of how to bring up
children and that Jem and Scout love her.