Just finished: The Girl in the Mirror by Rose Carlyle, about identical (mirror image) twins and their inheritance, which gets left in full to the first sibling who produces a legitimate heir. My only real complaint was that the pacing felt a little off--long stretches devoted to things that didn't seem important while scenes I wanted to spend more time with were rushed through, and I thought the flashbacks could have been woven in a little more neatly. But overall found it a very gripping story until the last page. Some reviews I read thought there was too much boat jargon (a good portion of the book takes place on a yacht), but as somebody with zero sailing experience it didn't bother me. I was always able to follow what was happening.
Next up: The Book of Lost Friends by Lisa Wingate.