Liane Moriarty: The Last Anniversary. 2006
Storpocket (kirppis).

Sophie has unexpectedly inherited Connie’s house on Scribbly Gum Island — home of the famously unsolved Munro Baby mystery. Sophie moves onto the island and begins a new life as part of an unconventional family where it seems everyone has a secret. Grace, a beautiful young mother, is feverishly planning a shocking escape from her perfect life. Margie, a frumpy housewife, has made a pact with a stranger, while dreamy Aunt Rose wonders if maybe it’s about time she started making her own decisions.