Who is Avanelle Shackleford from The Man Who Loved Clowns and what is their importance?

Avanelle Shackleford is Delrita's best friend. She moves to Tangle Nook when her father is unjustly sent to prison, and she lives in the tiny house next to McDonald's. Avanelle reaches out to Delrita when it becomes clear that neither of the them have any friends. Avanelle is described as short and skinny with wild, curly, red hair