Lady Oracle - Atwood, Margaret

The trick was to disappear without a trace, leaving behind me the shadow of a corpse, a shadow everyone would mistake for solid reality. At first I thought I'd managed it. Fat girl, thin girl. Red hair, brown hair. Polish aristocrat, radical husband. Joan Foster has dozens of different identities, and she's utterly confused by them all. After a life spent running away from difficult situations, she decides to escape to a hill town in Italy to take stock of her life. But first she must carefully arrange her own death.