Who is Nona Swopes from Blood Test and what is their importance?

Presented as the older sister of Woody, Nona is actually his mother. Her full name is Annona Blossom Swope and she is named for her father's horticulture enterprise. Nona is described as having been a sexual youngster though she is also very outwardly angry. Alex eventually discovers that she was raped by Mr. Swope - who she believes to be her father - from the time she is about thirteen. The rapes become a form of habit and she is pregnant at somewhere around fourteen. She is sent away to have the child though the neighborhood is told that she is being sent to boarding school.