When Mr. Hale questions Abigail during Act One, it becomes apparent that she is about to be blamed for Betty's illness and that she could be blamed for something even worse: inviting the Devil into Salem. He accuses her of concealing information, and, in the next moment, when Tituba enters the room, Abigail immediately accuses Reverend Parris's slave of forcing her and Betty to drink blood. She says, "She made me do it! She made Betty do it!" Surely, Abigail is aware that her word will be taken over a slave's and that this would be a good way to take some of the heat off of herself. Such a move is manipulative.
After Hale questions Tituba for a bit, Tituba gives him the confession for which he's been hoping, and he praises her highly for being "chosen to help [them] cleanse [their] village," and he promises that God will protect her. Abigail, seeming to sense an opportunity to be similarly praised, begins to accuse others of witchcraft, following Tituba's lead. She screams, "I want to open myself! I want the light of God, I want the sweet love of Jesus!" She confesses to straying from God and desiring to return to him. In this scene, then, we see Abigail deny participation in witchcraft and accuse Tituba in order deflect blame from herself; then we see her admit to what she formerly denied and use this admission to accuse others: manipulative, indeed!
In Act Two, Mary Warren gives Elizabeth Proctor a poppet that she'd made in court. Mary had stuck a pin into the poppet's stomach for safety, and Abigail had seen her do it. That night, at dinner, Abigail screamed, "And [Parris went] to save her, and, stuck two inches in the flesh of her belly, he draw a needle out." Abigail then claimed that it was Elizabeth's specter that pushed it into her stomach (knowing that Mary had taken this poppet home to the Proctors' house where it could be found and seem to confirm Abigail's story). She knows what people will think when the poppet and needle are found in Elizabeth's house, and she manipulates others with her knowledge of the poppet and the conclusions she knows they'll draw.