Not Without My Sister by Juliana Buhring, Celeste Jones, and Kristina Jones

Details:

Published in 2007 by HarperCollins.

Best guess I read it in 2008.

From the Publisher:

Kristina, Celeste, and Juliana were all born into the Children of God cult, and from as early as three years old were mistreated and used as sexual beings. They were denied access to formal schooling, forced to wander the streets begging for money, and were mercilessly beaten for "crimes" as harmless as reading an encyclopedia. After being separated from each other and their mothers and forced to live in various missions with multiple foster parents, the sisters eventually managed to escape. In this startling exposé, they have come together to reveal in horrific detail the group that has destroyed the lives of so many. Their intertwining stories reveal a community spread throughout the world whose legacy of anorexia, depression, drug abuse, suicide, and even murder are impossible to erase. Together, the sisters found a strength that finally enabled them to uncover and free themselves from the shadows of their past.

First Line:
In January 2005, our sister Davida died from a drug overdose.