What is the central idea of the text?

This is a thematic question. You might consider race as a central theme. From the very title, the theme of race permeates Woodson's Brown Girl Dreaming, intersecting with many other themes such as gender, age, family, and history. Woodson shows how the treatment of African Americans changed over the course of the 19th and 20th centuries, using her own family as an example. While Jacqueline enjoys much more freedom than her great-great-grandparents who were slaves, or even her own parents and grandparents who lived through the Jim Crow era, her experiences show that there was still much progress to be made during the 1960's and 70's.