Her debut picture book, And By the Way…, will arrive on bookstore shelves next spring, according to People. “I love being ‘Gamma Barbra’ to my three wonderful young grandchildren,” Streisand shared in a statement. The title of the book also has everything to do with Streisand, as it’s one of her signature phrases. Her stepson Josh Brolin has four children — who are the singer’s step-grandchildren. Josh Brolin shares Trevor, 38, and Eden, 31, with his first wife.