Answer: Their interaction shows that Isabel still believes in finding people with good hearts, despite being a slave and having had several mean "owners". A reflective tone is created in the book.
Step-by-step explanation: Isabel is forced to labor as a slave along with her little sister. Although Isabel passes through many ruthless owners, the fact that she has a good relationship with Becky, who is Madam Lockton's' housekeeper, proves that despite having had experiences of mistreatment with people in a higher position than her, she still believes in kind people. The book creates a reflective tone, since she's incredibly observant and brave, and the difficult situations she's put in made her a mature person at a very young age.