Who is Mrs. Wiley from Plum Island and what is their importance?

Mrs. Wiley is a descendant of one of the longtime residents of the area, and she is very old. She is somewhat cantankerous, but takes John and Beth to the land she sold to the Gordons. She did not want to sell the land, but she liked the Gordons so finally gave in. She had no idea what they wanted the land for, but had been told the Gordons just wanted a place to look at the view.