NORTHAMPTON — Rebekah Brooks is a jeweler with stores in Cambridge and Northampton. She says her upbringing in rural New Hampshire, in a house that resembles a sculpture, and her artist parents, provided her with a world of natural inspiration. Her mother still has the first necklace Rebekah made, hanging on the wall. After 15 years in New York, she and her husband decided they wanted a house and green grass. Brooks says the Valley seemed the perfect place because of its proximity to the city, interesting people, nature and culture.