The clairvoyant mother
At first the reader meets the mother of the novel and thinks, oh, this must be the Comfort Woman from the title, a reference no doubt to her role in Beccah's life. Beccah certainly suggests this interpretation in her own point of view, until the reader and Beccah simultaneously learn a difficult and life-changing secret about Beccah's mother Akiko. The title of the novel is not in fact a reference to motherhood; it is simultaneously a bitter pet name that Akiko was forced to wear during a season of intense sex slavery to the Japanese during WWII. By the end of the book, the mother's actively clairvoyant behavior is explained by the trauma she used spiritual psychology to manage. Often the trauma is unmanageable, which explains the mother's occasional fugue states.
Prostitution as a maternal symbol
Suddenly, the reader is asked to reinterpret Beccah's self in light of her ancestral news. What happens to her mother could have happened to her, she knows. This is the value of the symbolism as well; by forcing to make Beccah imagine her mother as a sex slave, her injustice is fully awakened. She now sees the human evil of sex trafficking and sex slavery with the empathy and love she feels toward her own mother. The symbolism also goes toward a more general point; the mother symbolizes all women who are the victims of sexual abuse.
Name change and symbolism
It is highly symbolic that Akiko kept her name, even though it was a dehumanizing way of reducing her sense of self. Why would Akiko not switch her name back to Soon Hyo? That symbolically points to the permanent ways that sexual abuse changed Akiko's sense of self and identity. The name change ends up being a convenient reminder of her grief and abuse. She identifies with the things that have happened with her more than she identifies to the feelings she had before. That makes Beccah understand her own self in a surprising light.
The forced abortion
The abuse has a symbolic center; Akiko is made to be pregnant by what was essentially rape, but then to make matters worse, the natural course of animal life is refused to Akiko. Against her will, she is aborted of the fetus in a medically heinous way that leaves her with a life of chronic health issues. She is physically damaged in a permanent way by the cruel role she was forced to play. They treated her like livestock whose main value was for sexual abuse. Beccah's mother's life was defined by difficulties with conception and motherhood, a horrific injustice.
The question of patricide
Beccah is radically transformed by the story of her mother. Now she is removed from the innocence of thinking her mother is just a loony clairvoyant type, and placed into the experienced understanding of her mother's suffering. In light of this, the original question of the novel becomes fascinating. The missing husband died, making both Beccah and Akiko pretty happy. The question is this: was Akiko able to summon enough magical power through her clairvoyance to entice "the gods" into killing her husband? She believes she is guilty, and that is good enough for some serious symbolic analysis.