Who is Helen Givings from Revolutionary Road and what is their importance?

Helen Givings is a socially aggressive, somewhat nosy Realtor. She sells the Wheelers their house on Revolutionary Road, and then takes it upon herself to fawn over the couple, visiting them and bringing them small gifts. She and her husband also entertain the Wheelers in their home, but Frank and April find the Givingses frightfully dull. Helen Givings eventually tells the Wheelers that their thirty-something son has been given passes from the nearby state mental institution to visit them and asks if they can bring him to the Wheelers' house to get acquainted. The first and subsequent encounters are disturbing and irritating to the Wheelers.