How had Abigail been previously employed in The Crucible?

Abigail Williams was formerly employed by John and Elizabeth Proctor as a sort of helper around the house: she would assist Elizabeth with taking care of the children, doing the cooking and chores, and so forth. The Reverend Parris asks Abigail about her dismissal from the Proctors' employment as well as her reputation in town. He asks this because it has been "seven month[s]" since she was "discharged from [their] service," and no one else has inquired about hiring her for the same kind of role.
Although Abigail protests her own innocence, blaming Elizabeth's personality for their parting, we learn from the conversation between her and John in act 1 that Elizabeth fired Abigail because she was having an affair with John. Abigail says to him, "It's she put me out, you cannot pretend it were you. I saw your face when she put me out, and you loved me then and you do now!" John admits their affair, and he expresses regret.  And though he may "think of [Abigail] softly from time to time," he is committed to his marriage and says that he would cut off his own hand before he ever reaches for her again.