What can the reader infer by Mary Warren giving the doll to Elizabeth so that Abigail might falsely accuse Elizabeth in act 2 of The Crucible?
We can reasonably infer that Abigail still has designs on John Proctor based on Abigail's request that Mary Warren give a doll to Elizabeth in the second act of The Crucible.
By giving Elizabeth this doll, Mary Warren sets the stage for Abigail's plot which is to accuse Elizabeth of performing witchcraft or voodoo against her.
Abigail pretends to feel a stabbing pain at dinner in front of many people. She accuses Elizabeth Proctor of causing her pain from afar. When the deputy comes to the Proctor house to follow up on the accusation, he finds a doll with a pin stuck into the belly under the dress.
This he connects with Abigail's recent falling to the floor with stomach pains which were found to be caused by a needle.
Abigail's story is thus corroborated by the doll which Mary Warren has planted in the Proctor house.
The act carried out by Abigail and Mary Warren indicates an idea on Abigail's part. She either wants revenge against Elizabeth or wants to reclaim John Proctor as her lover, or both.