Parents of a bad example
Even though this book is a memoir and not a novel, there is clearly a natural symbolism in Liz's experience that makes her story inherently archetypal and allegorical. At the end of the novel, we learn that the memoirist has made a successful and powerful person of herself, so that the shape of the allegory is clear: She is living proof that children can make themselves into successful adults—even those whose lives are painful because of their parents. The story has made Liz Murray into a force for good, because she is able to tell her story to people who have suffered.
The return of Daddy
Daddy is what Liz calls her father. She knew from a young age that her parents were drug addicts, but when she was young, her father was taken away from their home because of the legal consequences of his decisions. As a drug dealer of addictive narcotics, he earns himself a serious prison sentence. When he returns home, he is hyper-tense from the difficulty of life in prison, thirsty for his fix, and unhealthy in many other ways. The daughter experiences this as an introduction of pain and chaos into her home which was already difficult enough as it was.
Drugs and horror
Instead of treating drugs the way adults might—the way Liz's parents did for instance—the reader sees drug addiction through the lens of a child. For children whose parents struggle with illegal addictions, life can often become very hellish and insecure. That happens because children are especially dependent on their parents, and when the parents seem at odds with the broader community, the children are not able to trust their parents as easily. For the reader, Liz's real story takes on a nearly mythic level of confusion, insecurity, and fear.
The molestation
To attempt to explain what sexual assault "means" would be a travesty, especially when the victim is a young child. So, instead, consider the symbolism that the mother experiences by finding out that her daughter has been molested by a man whom she is sexual with in exchange for drugs. This symbolizes a kind of divine reckoning. She literally goes insane from the shame and self-hatred, according the memoir. That shows what the event symbolizes in her life. It symbolizes her finally having to admit that she has sacrificed her daughter's innocent life for her own indulgence and pleasure.
The decline and death of Ma
This memoir unintentionally captures a dichotomy between the mother and daughter. The mother gave the daughter a pretty harrowing circumstance for her to survive, and yet it is the daughter of disadvantage who ends up becoming educated, powerful, and heroic. Liz's mother suffers the allegorical downfall of those who indulge in addictions; she ends up dying in the AIDS epidemic as a result of her needle usage (probably) and the death symbolizes the tragic fate of addiction.
