Such Charming Liars, by Karen M. McManus

After years of life as a jewelry thief, Kat's mother has finally decided to go clean.  She just needs one more job to make a new life possible.  It ought to be pretty straightforward: under the cover of being a caterer for a rich guy's 80th birthday run off with a valuable ruby necklace that belongs to his daughter while everyone is distracted blowing out the candles.  But things go wrong from the start:  on the way to site, their car gets a flat tire and the person who stops to help them is hardly a stranger.

Years ago, Kat's Mom married a man in Vegas and his son Liam was friends with Kat for 48 hrs.  But after a series of best-left-forgotten adventures, Mom and Dad split up non-amicably.  And now by strange fate they've suddenly been reunited, but it's not random chance: Liam's father is catfishing the same rich guy's daughter.  So, we have two con artists targetting the same person for very different reasons and their children are thrown into the middle of it all.

The story's a LOT more complicated than this, of course (especially when we start stacking up dead bodies), and there are layers upon layers of crosses and double crosses.  In the midst of all that story, it's easy to lose track of the characters and forget who is what to whom.  The characters are not particularly memorable and the plausibility of the plot wanes as things get complicated, but none of that really matters.  This is a well thought-out story and it's great fun to take a ride on the adventure, but it wasn't much to my taste. I had to wonder in the end if any of this made much sense.