This seems to be the week of murder novels for me. This reminded me a bit of Mr. Peanut; there is a secret here (besides the murder/who-done-it) and the novel opens with the scene in which Karen's secret threatens to be revealed.
I found the constant "da-dums" at the end of chapters to be annoying. Almost every chapter about the "summer of love" ended with a reference to "but our happiness would not last" or some other sort of reminder that darkness and murder was awaiting. I didn't think this was necessary to keep rubbing our faces in it, it was compelling and the characters were interesting enough, the added drama just made me roll my eyes.
I also did not find Alice to be a believable character. She is supposed to be almost 10 and yet she acts younger than my 7 year old. A single precocious child at 10 is much more adult-like than Alice is portrayed.
I did figure out as soon as she went to Switzerland and got fat that she was never pregnant. Karen was much too responsible to do all that drinking or leave the country if she was pregnant. And so, I figured it must be Biba's daughter (how else would Alice be so similar to Rex). Then, after it is revealed and Rex starts to talk about having another, I remembered the Secret Life of CeeCee Wilkes (which is the only other book I have read in which a woman pretends her way through a first pregnancy as if it is her second).
I did not understand Karen's fear of the police, though, leading up to Biba's return. At this point, Karen believes Biba to be dead; she thinks that Arouna and herself are the only two that know that Biba was pregnant (INCLUDING THE HOSPITAL THAT DELIVERED ALICE). And so, there is really no one who can reveal that Alice is not Karen's daughter. Even if there was, the state system is not likely to prefer Alice be an orphan child; Rex is next of kin (assuming Biba is dead) and Karen is (almost) Rex's wife. I get that Rex and Alice will feel betrayed and upset (but wouldn't Rex anyway forgive her pretty quickly, after all he also thinks Biba is dead and would appreciate Karen taking over and being responsible).
I do get why she would kill Biba and certainly after Biba's death Karen would now have reason to fear the police; but I think some of the paranoia that is written into the earlier chapters is a results of Erin Kelly's knowledge of what Karen is going to do, rather than what is chronologically accurate within the story.
Overall it was a compelling, interesting read. Nothing fabulous but the story holds together for the most part and it was entertaining.