How does Sofia escape jail in The Color Purple?

Sofia gets sentenced to twelve years in jail for sassing—talking rudely—to the mayor's wife and for hitting the mayor. As Celie puts it in a letter to Nettie,

Polices lock her up for sassing the mayor's wife and hitting the mayor back.

Sofia, Celie goes on to say, was "dying" working in the prison laundry, so the family managed to get her jailed instead in the mayor's house. After serving eleven and half years, Sofia was paroled for good behavior so that she could be with her family:

Anyhow, they kept her eleven and a half years, give her six months off for good behavior so she could come home early to her family.

The episode is an indictment of the way the justice system treats Black people. Sofia served a long sentence for very minor crimes, and being released six months early was no great act of charity. As Celie notes, by the time Sofia got back home, her older children had grown up and left, and the younger children did not remember her.

Sofia notes that she is on parole and has to behave herself. When she first comes home and is eating dinner with the family the first night, the children act as if she isn't there.

Celie, who uses this as the time to announce that she is going to leave after Nettie comes with her children, blames Harpo for Sofia ending up in jail. Harpo denies it, but Sofia says there is some truth in the statement.

How long was Sofia in jail in The Color Purple?

Sofia is sentenced to twelve years in jail for striking the white mayor and "sassing" the mayor's wife. The mayor's wife, impressed by how clean Sofia's children are, offers Sofia a job as a maid. Sofia responds with an unambiguous "Hell no." The mayor slaps Sofia for what he perceives to be her insolence, and in response, Sofia "knock[s] the man down." For that retaliatory strike, Sofia pays with twelve years of her life.

After Sofia strikes the mayor, the police arrive. The police proceed to mercilessly beat Sofia. They "crack her skull, they crack her ribs," and they continue beating her until she is "just about the color of an eggplant."

While in jail Sofia is put to work in the laundry. She spends fifteen hours every day washing clothes and sheets. Sofia does this for eleven and a half years, and she tries her best in this time to be a model prisoner. Harpo suggests that perhaps she might get out early for good behavior, but Sofia tells him that "good behavior ain't good enough for them," meaning the prison officers. Being in jail for nearly twelve years of course takes its toll on Sofia. She says that while she is in jail she "dream(s) of murder," not only when she is asleep but also while she is awake.