Mary Warren is portrayed as a timid, shy girl who fears Abigail Williams and bends to her authority at significant moments in the play. While Mary Warren and Abigail appear to be friends on the surface, Abigail intimidates and threatens Mary Warren to corroborate her story and feign madness during the court proceedings. Abigail Williams is a confident, callous young woman, who threatens to kill Mary if she tells the truth about what happened in the forest. Mary fears Abigail Williams and trusts that she will prevent them from being punished. Mary Warren is also aware that the citizens respect and admire Abigail and enjoys the perks of being one of her followers. Abigail essentially uses Mary Warren as a pawn to advance her social status and seek revenge on Elizabeth Proctor. Abigail knows that Mary is easily influenced and demands that she follows her lead. Whenever Mary Warren threatens to undermine the court by testifying that Abigail and the others are lying, Abigail turns the tables on Mary and begins to act like Mary's spirit is about to attack them. Mary Warren is aware that she is in a dangerous position and ends up supporting Abigail by accusing John Proctor of conspiring with the devil at the end of act three. Overall, Abigail and Mary's relationship is one-sided. Abigail essentially manipulates and uses Mary for her own selfish purposes.

On the surface, Mary Warren and Abigail Williams seem to be friends.  They are the same age, and they were both present with Tituba the night before the play begins, attempting to conjure the spirits of Mrs. Putnam's dead babies.  Further, Mary now occupies the position in the Proctor household that was vacated when Elizabeth Proctor discovered the affair between her husband and Abigail seven months ago.  After she fired Abigail, she hired Mary.

Under the surface, however, it does not seem like Abigail and Mary are really very friendly.  Mary is introduced as a "lonely girl" (implying that she has few real friends, if any) and she and Abigail are at odds right away about whether or not to confess what else they were doing in the woods.  Mary wants to tell, but Abigail will not.  In fact, Abigail dramatically threatens to come to any of the girls at night, with a "pointy reckoning," and "make [them] wish [they] had never seen the sun go down" if they tell.  Threatening with knives is clearly uncommon behavior between friends.