Virginia Euwer Wolff celebrates humanity’s resourcefulness in dire circumstances - the ability to produce a tiny stash of sugar to sweeten the sour fruit of experience. Her familiar material - urban poverty, the hard grind of parenting on the margins of society and children’s enduring capacity for fun and learning - is lifted into something extraordinary by the prose-poem form and the energy of the narrator Verna La Vaughn’s rap rhythms.

La Vaughn is a bright working-class high-school student whose brain is her ticket out of her run-down neighbourhood. The inner-city United States setting and the characters’ ethnic background are deliberately non-specific: any reader can identify with La Vaughn or Jolly, the 17-year-old single mother who hires her as a babysitter.

The intense, forceful narrative, compelling enough to read in one sitting, is a subtle treatment of the shifting power balance between the two teenagers and the walk-on roles which relative privilege and exploitation play in the drama of their relationship. La Vaughn earns money to save for college from Jolly, who had to drop out of school; the employee takes on responsibility for her employer’s problems; eventually Jolly can’t afford to pay La Vaughn, but needs her help. Who is exploiting whom?

Fear is another key player. Jolly’s history of homelessness and abuse and her “dropout” lifestyle spells dreaded destitution and moral decline for the respectable, upwardly mobile poor, such as La Vaughn and her mother (also a single parent, but a widow and therefore socially acceptable). La Vaughn, reared to strive for self-improvement, feels threatened by the chaos in Jolly’s home: “I put one finger up to wipe offjust a little bit of yuck off the glassto see me betterand I’m afraid . . . and I’ll end up old and no collegewith back rent to payand looking at cockroaches for my entertainment”. Finally, this is a study of growing up through a series of breakthroughs. As Jolly’s two children learn to walk, count and grow lemon trees, both their mother and their carer become better equipped to face the future.

Joan Lingard’s Lizzie is looking for a better life too, but her grasp on reality is more feeble than La Vaughn’s or Jolly’s. Lizzie seeks out Mark, the father who deserted her mother before she was born. She sees Mark as an escape from boisterous family life with her mother and stepfather, and goes to live in his more sophisticated household. Mark is fantasy fodder down to his thick dark hair and crinkly-eyed smile, straight out of a teen romance. He takes his “new” daughter to expensive restaurants and flatters her, but when it comes to meeting Lizzie’s needs he cannot match the kind but ordinary newsagent who has helped to bring her up.

Lizzie’s Leaving charts the erosion of Lizzie’s fantasy, exposed in letters home, her sister Alice’s diary and straight narrative. The cracks appear too slowly. Lizzie comes over as a shallow, naive, misguided creature, a much less sympathetic character than sharp, witty Alice, who would catch the next train home if Mark and his cold-hearted yuppie wife treated her as a free au pair, as they do Lizzie.

Alice’s struggles with her shyness hold more interest than Lizzie’s predictable traumas and her position at the heart of a friendly community is part of the past that Lizzie has exchanged for isolation chez Mark. Her passage through misery and anger is touching but the plot becomes increasingly fragile and the sitcom-style ending smacks of desperation.