The Rose Garden by Susanna Kearsley
When Eva's film star sister Catrina dies, she leaves California and returns to Trelowarth, Cornwall, where they spent their childhood summers, to scatter Catrina's ashes and thus return her to the place where she belongs. But in doing so Eva must confront ghosts from her own past, as well as those from a time long before her own. For the house where she so often stayed as a child is home not only to her old friends the Hallets, but also to the people who had lived there in the eighteenth century. Eva finds herself able to see and talk to these people, and she falls for Daniel Butler, a man who lived and died long before she herself was born. Eva begins to question her place in the present, and in laying her sister to rest, comes to realise that she too must decide where she really belongs, choosing between the life she knows and the past she feels so drawn towards.