Whisper Island (2007)

Sam Dalton is determined to save the only home she has ever known, the faded, dusty Romanian Princess ranch. Sam writes to a distant relative of her Aunt Christine hoping he can prevent the ranch from being repossessed. But it's J. T. Swinton, a teen-age boy who shows up. In desperation they turn to a seemingly futile hope, the treasure of Whisper Island. But does the Civil War treasure really exist? The answer seems to be trapped somewhere in the wishful delusions of Aunt Christine. As the teens search for treasure in a race against time, they must also search Christine's past and unravel a web of romance, intrigue and betrayal that spans a lifetime and beyond. What they find, changes their lives forever.