what item in the housekeeper's necklace kept the soul from wandering the earth?
Johnna, the Native American housekeeper hired to take care of Violet Weston, is the primary witness of the mayhem in the Weston household and of the dysfunctional nature of the Westons as a family.
Johnna, as a Cheyenne Native American woman, abides by the traditions of her ancestors. She owns a talisman, that is, a charm that represents something, and she wears it around her neck.
This necklace contains her own umbilical cord inside of a pouch. In Johhna's own words:
because if we lose it, our soul belongs nowhere and after we die, our souls wander around the Earth looking for where we belong.
This is an ironic statement considering that her employer, Violet, is literally part of the living dead. She spends her entire day high on prescription pills and other drugs. Violet is entirely responsible for the destruction of her family. Her addiction has dragged an entire family with her. Johnna's charm is mostly a need for Violet than it is for herself.