When Bob Ewell testifies, he says that he heard Mayella screaming and came up to the window to see Tom Robinson raping her.
Well, Mayella was raisin' this holy racket so I dropped m'load and run as fast as I could but I run into th' fence, but when I got distangled I run up to th' window and I seen-" ... He stood up and pointed his finger at Tom Robinson…(ch 17)
He then claimed he ran into the house to find Mayella on the ground, and could not run after Tom Robinson. Instead he called Heck Tate.
Mayella claimed she was on the porch and Tom Robinson passed, and she asked him to bust up a piece of furniture.
So he come in the yard an' I went in the house to get him the nickel and I turned around an 'fore I knew it he was on me. Just run up behind me, he did. (ch 18)
She them claimed when her father came in she fainted.
When Atticus cross-examines her, Mayella gets confused.
"No, I don't recollect if he hit me. I mean yes I do, he hit me." (ch 18)
Mayella does her best to confirm her father’s testimony, but she gets the lies a little mixed up. In the end, it is obvious that Tom Robinson could not have done it.
Mayella is a young girl in a bad situation. She tries to follow her father’s lead and accuse Tom Robinson, but Atticus confuses her and mixes her up. Despite the fact that nothing happened, Robinson is still convicted because he admits he felt sorry for Mayella, and a black man cannot feel sorry for a white woman in Maycomb in the 1930s.
I agree with the answer above except for that Mayella doesn't necessarily try to follow her father's lead. Her father was threatening her against her will. You can see it when Atticus is questioning Mayella Ewell:
“I mean, is he good to you, is he easy to get along with?”
“He does tollable, ‘cept when—”
Mayella looked at her father, who was sitting with his chair tipped against the railing.
He sat up straight and waited for her to answer.
“Except when nothin‘,” said Mayella. “I said he does tollable.”
Mr. Ewell leaned back again.
“Except when he’s drinking?” asked Atticus so gently that Mayella nodded.
“Does he ever go after you?”
“How you mean?”
“When he’s—riled, has he ever beaten you?”
Mayella looked around, down at the court reporter, up at the judge. “Answer the
question, Miss Mayella,” said Judge Taylor.
“My paw’s never touched a hair o’my head in my life,” she declared firmly. “He never
If she told that truth about her father, than Mr. Ewell would just beat her more when he is drunk. You can see that he threatens to beat her by sitting up straight.