The Girl in the Mirror by Rose Carlyle

Identical twins only look the same...

Beautiful twin sisters Iris and Summer are startlingly alike, but beyond what the eye can see lies a darkness that sets them apart. Cynical and insecure, Iris has long been envious of open-hearted Summer's seemingly never-ending good fortune, including her perfect husband, Adam.

Called to Thailand to help sail the family yacht to the Seychelles, Iris nurtures her own secret hopes for what might happen on the journey. But when she unexpectedly finds herself alone in the middle of the Indian Ocean, everything changes.

Reasonable used condition.