What does Abigail claim is the reason she was discharged from the Proctor household in The Crucible?

Abigail claims that Elizabeth Proctor fired her because she would not be her slave.

Abigail was fired for having an affair with John Proctor.  Proctor admits to the affair in court.  His wife knew about it, and obviously did not want Abigail around the house.  However, in court Abigail claimed a very different reason for being fired. 

Abigail: She hates me, uncle, she must, for I would not be her slave. It.’s a bitter woman,...

Abigail claims that Elizabeth Proctor fired her because she would not be her slave.

Abigail was fired for having an affair with John Proctor.  Proctor admits to the affair in court.  His wife knew about it, and obviously did not want Abigail around the house.  However, in court Abigail claimed a very different reason for being fired. 

Abigail: She hates me, uncle, she must, for I would not be her slave. It.’s a bitter woman, a lying, cold, sniveling woman, and I will not work for such a woman! (Act 1)

Abigail’s attempt to discredit Elizabeth Proctor is part of her plan to get John Proctor back, apparently.  It seems that she has been making eyes in him at church for months.  Although Proctor admits that he was seduced by her in a moment of weakness, he tells them that he ended it.

Abigail definitely has some character flaws.  Besides sleeping with another woman’s husband, she takes a vigorous part in the trail, condemning innocent people to make herself look better.  Abigail is a bitter and selfish woman who behaves immaturely and does not seem to care about the consequences of her actions.

When Elizabeth is cross-examined about dismissing Abigail, she cannot bring herself to admit the affair at first.  She just says that the girl dissatisfied them both.  When Danforth presses, she admits what happened.

Elizabeth: I came to think he fancied her. And so one night I lost my wits, I think, and put her out on the highroad. (Act 3)

Interestingly enough, what saves Elizabeth from the noose is telling the court that she is pregnant.  They do not believe her at first, but it soon transpires that she is telling the truth.  They agree not to kill her so she can have the baby.

Abigail's case is a perfect example of what really happened in the Salem Witch Trials.  Anyone with a grudge could get ride of an enemy and get what she or he wanted just by accusing someone.  It is clear that Abigail is a woman of little character, but they believe her anyway and she sends good people to their deaths to serve her petty purposes.