Stephane Cardinale – Corbis/Getty Images Keira Knightley is sharing rare insight into life as a wife and mother. The Black Doves star, 39, has been married to British musician James Righton since 2013. The couple share two daughters, Edie, 9, and Delilah, 5. “It’s good for an actress and a musician, isn’t it?” Knightley said…