Author Karen Cushman is no stranger to the medieval and Renaissance world. Her first novel, the Newbery Honor book “Catherine Called Birdy,” examined the period from the perspective of a noble-born girl waiting to be married off. The author’s latest work, “Will Sparrow’s Road,” is set during 16th-century England and its title character lives a life that Birdy could only “[fantasize] about as she sat inside embroidering.”