Patricia A. Cochrane's 1996 intermediate-level novel, Purely Rosie Pearl, tells a realistic story about a close-knit family of migrant workers struggling to survive during the Great Depression. The central character, tow-headed twelve-year-old Rosie Pearl Bush, is feisty and engaging, her optimistic nature undaunted in the face of the harsh conditions of her family's situation. The narrative is set in California's Sacramento Valley in the mid-1930s; the Bush family harvests apples in Yakima, Washington during part of the year, and travels to California to pick berries and other fruits in the summer.

At the migrant camp, Rosie Pearl meets Maggie Campbell, a city girl her own age whose family has newly fallen upon hard times. At first, Rosie Pearl perceives Maggie as being snobbish and uppity, and Maggie thinks Rosie Pearl is nothing but a tramp, but both girls soon learn to look beyond their differences and become fast friends. Rosie Pearl teaches Maggie the finer points of migrant life, and the two share confidences and adventures over the long summer months. When the sleazy overseer, Jake Porter, accosts Rosie Pearl and taunts her and her family for not having the gumption to rise above their station, her confidence is momentarily shaken and she begins to think seriously about her life. Because of the family's forced employment situation, Rosie Pearl's time in school has been sporadic, but with the help of Maggie, who endeavors to teach her to speak more grammatically, Rosie Pearl begins to take active steps to improve her lot in life.

Although the story takes place specifically in the distant historical past, the author focuses on issues which are hauntingly relevant to the present day. The power of a caring and supportive family is a central theme, as the characters struggle against adversity with dignity and strength in difficult economic times. The value of education as a means to a better life is also stressed, as Rosie Pearl strives to complete her schooling and go on to college despite the obstacles to learning presented by her family's itinerant lifestyle. Finally, the thorny issue of accessibility to health care is directly addressed. Rosie Pearl's sister Lily Opal, depleted by hardship and poor living conditions, has a difficult pregnancy, and her premature baby eventually dies because a local private hospital turns mother and child away because of inability to pay. It is this tragic experience in particular which galvanizes Rosie Pearl in her resolve to do "whatever it takes" to ensure that "nobody in (her) family would ever again be kept from having help because they were migrants."