Did Mary Warren know how the poppet she gave Elizabeth would be used?

Your question relates to the dramatic events in Act 2 and seems to ask whether Mary Warren was aware that the poppet she made as a gift for her employer, Elizabeth Proctor, would be used as a tool by the diabolical Abigail Williams to implicate Elizabeth as a witch. The answer, in this instance, is no. Mary made the doll in court as a gift for Elizabeth.

Mary Warren, glancing about at the avid faces: Why—I made it in the court, sir, and—give it to Goody Proctor tonight.

She also mentions that Abigail sat next to her and saw her fashion the doll and had witnessed her inserting the darning needle into the doll's belly once she had finished.
That evening, Abigail had screamed out in pain during dinner at her uncle's (the Reverend Parris) house and fell to the floor. The concerned Reverend approached her and extracted a needle from her stomach. Abigail claimed that Elizabeth had bewitched her by using the doll. Her devious act leads to the issue of a warrant for arrest against Elizabeth. She will be arrested for witchcraft if a doll is found in her possession.
When Ezekiel Cheever and Marshal Herrick arrive at the Proctor home to serve the warrant, the former is aghast to find the doll with a needle stuck in its stomach. He firmly believes that this is irrevocable proof of Elizabeth's evil. Cheever ignores Mary Warren's testimony and is intent on arresting the innocent Elizabeth. John Proctor is overcome with rage and tears up the warrant, but Elizabeth later convinces him that she should accompany the arresting officers.
John Proctor then demands that Mary should accompany him to court the next day to tell the truth. The poor girl is terrified and insists that she cannot go, because she believes that Abigail will kill her and that all the girls will turn against her. She tells John that Abigail will charge him with lechery. He, however, has only Elizabeth's interests at heart and tells Mary that both he and Abigail will be damned but that he will not allow his good wife to die for him.
The scene closes with an utterly distraught Mary Warren repeatedly sobbing that she cannot testify.