Significance of Butterfly Necklace

Marie’s butterfly necklace represents her connection to her family, specifically Tess, as Hazel gave it to her when Tess was born. That Eleanor forbade personal belongings, and thus the necklace, during training speaks to the fact that Marie feels removed from her daughter after accepting the position. This becomes even more apparent as she leaves the butterfly necklace with Eleanor when she finally deploys, indicating an even greater removal from her daughter as she is now in enemy territory and thus in danger.