I was just telling a friend that I rarely leave two-star reviews, but this is one of them. I probably wouldn't have read the entire book (Davina Porter's usual terrific narration notwithstanding), except for the resolution of the "mystery" presented at the outset; to avoid a spoiler, I'll leave it that Smith handles that aspect well in terms of a surprise.
What isn't handled so well are the characters - there wasn't a single one I care to hear about enough to read the second book in this series. The protagonist Isabel seemed considerably older than 42 to me - her "editorship" of an obscure journal seemed more of a make-work project than anything else; basically, she's independently wealthy, which isn't a bad thing, but she seems to live vicariously through others, when not obsessing over details. Her niece Cat struck me as rather a spoiled brat; sorry, but there it is. Grace, the housekeeper, is "wise", which is compensation I suppose for being neither rich nor very good looking, as with every other character in the story. The beautiful Jamie struck me as a wimp; moreover, Isabel (and Grace's!) focus on how hot he is struck me as a tad unseemly - I wouldn't have liked seeing male characters doing so either. Another reviewer stated that she felt Smith's women struck her as being written by a man, who thinks he knows how women think, but doesn't quite get it (paraphrased). I've never been a woman myself, but I think that person may have been onto something.
The story is cozily, quaintly character-driven in a similar manner to the No. 1 Ladies' Detective series, but lacks the spark of those tales. Perhaps the difference can be explained that Mma's Ramotswe and Makutsi (the latter especially) have made something of their lives, without having it handed to them, unlike Isabel and Cat.
So ... I wasn't sorry I read the book, but can't recommend it with any enthusiasm.