The only place I have found this story is in the Australian Women's Weekly of 18 August 1965. This would make it one of Canning's last short stories.
A doctor's daughter visiting Venice is picked up by an elderly expatriate millionaire. Rejecting the advice of her reliable British friend she goes to stay at the millionaire's villa, where she is told that she resembles his dead daughter and must wear the clothes and jewellery that the daughter would have worn on her last birthday. The staff at the villa, meanwhile, have sinister intentions.
Frankly, this is one of Canning's weaker efforts, perhaps having been dashed off hastily.
Australian Women's Weekly, 18 August 1965.
Included in the collection Italy and the Balkans, ed. John Higgins.