Had not Mayella "broken a rigid and time-honored code of our society"--tempting a black man and then accusing him of raping her--she would be deserving of the pity of most of the people of Maycomb. She is the daughter of Bob Ewell, the most reviled man in town; yet, aside from her indiscretion with Tom, Mayella is innocent of any wrongdoing. She is left alone at home with her seven brothers and sisters, serving them as the mother they do not have. She lovingly tends to her geraniums, the only thing of beauty found on the Ewell property, and she has given up any chance of a decent social life or education. She is subject to whatever abuses her father may have in store for her, and Scout soon sees that
... Mayella Ewell must have been the loneliest person in the world. She was even lonelier than Boo Radley... (Chapter 19)
But Mayella falls prey to her own temptations, and when she plots to maneuver Tom inside her house, he resists her advances. When Bob catches Mayella hugging and kissing Tom, he beats her and then creates the story of Tom raping her to cover for her mistake. The fact that Mayella agrees to back her father's story, which puts an innocent man in jail with the prospects of a death sentence hanging over his head, is a revolting decision to undertake. She maintains her own innocence, brands Tom a rapist, and hatefully refers to him as "that nigger yonder" while tearfully trying to gain the sympathy of the jury. In the end,
... if she hadn't been so poor and ignorant, Judge Taylor would have put her under the jail for the contempt she had shown everybody in the courtroom. (Chapter 18)
Instead, Mayella will carry on the family tradition of being "the disgrace of Maycomb" for another generation.