Random House Australia are currently offering Ghost Child by Caroline Overington as a free download. Its selling for AU$22 at Borders Au so its a good bargain

You need to subscribe to their newsletter to get download link. Goto
www.randomhouse.com.au I subscribed a while ago and they only send about one email a month. If you are already subscribed the link is in the newsletter. Not sure if it is geo-restricted to AU/NZ.
Here's a summary taken from Amazon.
In 1982 Victorian police were called to a home on a housing estate an hour west of Melbourne. There, they found a five-year-old boy lying on the carpet. There were no obvious signs of trauma, but the child, Jacob, died the next day.The story made the headlines and hundreds attended the funeral. Few people were surprised when the boy's mother and her boyfriend went to prison for the crime. Police declared themselves satisfied with the result, saying there was no doubt that justice had been done. And yet, for years rumours swept the estate and clung like cobwebs to the long-vacant house: there had been a cover-up. The real perpetrator, at least according to local gossip, was the boy's six-year-old sister, Lauren...Twenty years on, Lauren has created a new life for herself, but details of Jacob's death being to resurface and the story again makes the newspapers. As Lauren struggles with the ghosts of her childhood, it seems only a matter of time before the past catches up with her.