Soul Beach (Soul #1) by Kate Harrison

When Alice Forster receives an email from her dead sister she assumes it must be a sick practical joke.

Then an invitation arrives to the virtual world of Soul Beach, an idyllic online paradise of sun, sea and sand where Alice can finally talk to her sister again - and discover a new world of friendships, secrets and maybe even love. . .

But why is Soul Beach only inhabited by the young, the beautiful and the dead? 
Who really murdered Megan Forster? 
And could Alice be next?