Who is Alafair from Heaven's Prisoners and what is their importance?

Alafair is a young girl who flees Nicaragua with her mother to escape the violence of civil war. Alafair is the only survivor of the plane crash witnessed by Dave and Annie in the opening scene of the novel. Alafair is subsequently, and unofficially, adopted by Dave and Annie and subsequently lives with them. After Annie is murdered Alafair is shuttled between Batist and one of Dave's cousins until Robin Gaddis arrives and provides stable home care. Alafair speaks only Spanish but learns some English by the end of the novel. Although present in many scenes she is not a notable character in the book and functions mostly as motive force for Dave's desire to right the wrongs of the world. Because she is a war refugee, she awakens in Dave many memories of Viet Nam.