Here's a backlist title, free today from Amazon, with a long history:
Rose, Rose Where Are You? by Nicola Thorne.
It appears to have first been published under the same name by Rosemary Ellerbeck (a pseudonym of Thorne) by Hale in 1978. In 2004 it was published by Severn House as The House By The Sea by Nicola Thorne.
Publisher's Weekly description: ‘A captivating French seaside Gothic romance with supernatural overtones … history, spookiness and suspense.’