I think the incident with the poppet that Mary Warren made for Elizabeth in Act II of this excellent drama shows the evil nature of Abigail and how she is plotting to have Elizabeth killed through an accusation of witchcraft. It definitely shows the premeditated nature of her attack against Elizabeth. Note the way that she carefully planned it, either watching Mary Warren planting a needle in her poppet or putting it in herself as she sat next to Mary Warren as she was making it. She then used this as an opportunity for another demonstration of how she is being attacked by witchery, as Cheever shares with the Proctors:
The girl, the Williams girl, Abigail Williams, sir. She sat to dinner in Reverend Parris's house tonight, and without word nor warnin' she falls to the floor. Like a struck beast, he says, and screamed a scream that a bull would weep to hear. And he goes to save her, and, stuck two inches in the flesh of her belly, he draws a needle out. And demandin' of her how she come to be so stabbed, she testify it were your wife's familiar spirit pushed it in.
Abigail is thus cold-heartedly and cruelly willing to harm herself to succeed in her goal of disposing of Elizabeth so that she can be with John Proctor. However, the intelligence with which she has thought her plan through is rather chilling, to say the least, and indicates the way in which the Salem Witch Trials were used as an excuse to settle old scores for so many, not just the Putnams.