Showing Charley's Web by Joy Fielding

Charley Webb is a smart, beautiful single mother-of-two who left New York City in search of her own version of paradise in Palm Beach, Florida. She now writes a column for the Palm Beach Post, in which she shares her views on sex, shopping and the more entertaining goings-on in her neighbours' lives - much to their disgust.
Charley knows she's not the most popular person in town - but then she receives a letter from a genuine fan. Jill Rohmer is a young woman serving time on death row for the murders of three small children - and she wants Charley to write her biography. For there are many hidden truths surrounding the murders Jill is now ready to reveal, including the existence of a mysterious man she calls Jack.
But as Charley begins to delve into Jill's background, she starts receiving threatening, anonymous letters regarding her own children. Jill is safely locked away - so does this mean the elusive Jack is still out there somewhere?
Charley finds herself in a desperate race against time to unlock the secrets behind the murders before her own family becomes the killer's next target.