Chapter 2 is essential to understanding the question you pose. Through the character of Miss Caroline Fisher, Harper Lee allows the reader to discover "the intricacies of the Alabama town" even though Miss Caroline doesn't understand this system at all.
Through Scout, the reader learns of the caste system in Maycomb county. In this system, the Finch family is at the top, followed by the Cunninghams, Ewells, and then the Robinsons. Even though the proverty-stricten Walter Cunningham is not in the same class as Scout, he is placed higher within the caste system than Burris Ewell, who is poor white trash. Although Walter is poor, his family will not accept charity and that is what Scout is trying to explain to Miss Caroline, who insists upon giving Walter money when she discovers he has no lunch.
In addition, Miss Caroline does not understand Scout's upbringing from a sophisticated, well-respected family. Scout reads fluently, and the teacher scolds her while insisting that she learned how to read incorrectly.
The fact that Scout is trying to explain Walter's plight to Miss Caroline, reinforces that Atticus' family values of raising his children properly is working. Scout is employing Atticus' motif of understanding people by "walking in their skin."