Romney's Sister: Just published: Mitt Romney: An Inside Look at the Man and His Politics by Ronald B. Scott.
Ben Smith notes the book takes a closer look at the Romney family. Romney's eldest sister Jane, an actress who lives in Los Angeles is described "the Billy Carter of the Romney family" in part because she openly backed Sen. Barbara Boxer (D-CA) and campaigned for California Gov. Jerry Brown (D). She also had a "very acrimonious divorce" from a nephew of the head of the Mormon church.
Jane Romney apparently "is eager to have a visible role on her brother's campaign which, in turn, is eager to keep her busy and out of trouble."