Elizabeth Proctor does not appear in Act I. However, her opinion of Abigail is known from the conversation between John and Abigail.
Elizabeth Proctor fired Abigail from their household because she found out that she and John were having an affair.
It is in the beginning of Act II, that we hear Elizabeth's words for the first time in the play.
Elizabeth knows that Abigail still wants her husband and that she would like Elizabeth dead.
"She wants me dead, John you know it!" (Miller)
She asks her husband to go and tell Abigail that she is a whore.