In this quote by Scout the author is letting us know that the Ewells are not accepted by the other classes in Maycomb. They get hand-outs, they get
"Christmas baskets,they get welfare, "and the back of its (Macomb) hand."
The Ewells are isolated in Macomb. White people don't have anything to do with them because of the way they live, according to Scout, and black people don't deal with them because they are white. Scout is beginning to realize that Mayella must be as lonely as Boo Radley.