The allegory of a disappointing daughter
This is the story about a daughter whose mother has died, meaning that the question of the novel will be about family, honor, and duty. By duty, we mean that perhaps Grace has a destiny to fulfill that she is obligated to fulfill to honor her family. All these factors make Grace into an allegorical character who represents anyone who tries to forgive their parents, while still being honest about their mistakes and issues.
The symbolic aunts
When Grace looks for answers in Singapore, she re-encounters the women of her family who remind her of their unfair expectations about how "Australian" she is supposed to feel, or how closely she should relate to the family. These female voices are like echoes of what Grace feels her mother expected. Therefore, they are a metaphor for her working through her beef with her mom.
Australia as a symbol
Australia was supposed to be a better place for Grace because it gives her a chance at a higher education and a better life, especially as a woman. However, Grace's experience of Australia is darker and more lonely than they could know. For Grace, Australia represents absolute isolation and detachment from her family.
Vertigo
Vertigo is severe disorientation caused by heights. The plane rides give Grace vertigo, but this is mostly metaphorical: By traveling so much, Grace isn't able to set down roots. Her identity lacks a cultural home base. She is disoriented in life because of the constant plane flights.
The allegory of the migrant
Because this story captures the feelings of loneliness, confusion, and dilemma that shape immigrant experiences, it serves as an allegorical reminder that life is emotionally painful for immigrants and refugees, because of the change that moving brings, because of the difficulty of adaptation, and because of the loneliness and separation from one's family, both physically and culturally.
