I read this book a few years ago, and got on this page to buy it for a French friend.
I have to say I'm astonished at some of the negative comments I have read. Some readers just didn't get it at all and I understand why.
This book is second or third degree humour! It takes a specific audience to enjoy it, and the title is pretty clear on who the target is: French people living in the UK. I think English people can enjoy it too, but only if they speak good French, and please do not take it seriously.
A lot of the jokes come from play on words and expressions, and if you don't know the French and English meaning, then you can't see why it's funny.
I'll give you one example: she goes on about the fact that "not taking yourself seriously" is seen in the Uk as a quality, whereas in France saying that a man is "un garcon serieux" is a compliment. This plays on the fact that the French use the word serious here to mean responsible, whereas the English use the expression to mean someone who has a high opinion of themselves. Now she does it in a witty and candid way, which make her remark funny (and I'm not doing it justice), but if you don't know both languages well enough to appreciate their subtleties, then you miss the pun entirely, and when it is being explained, the humour gets lost too. This is not the only form of humour she uses, but the book is full of these, and I can see that non bilinguals stand no chance of getting it. It's only funny if you get it instantly.
This book was not written by a French woman living in London, but by an English woman who has lived in Paris for a few years. I'm impressed at how well she understood both nations and languages to come up with this.
It's a p1ss-take of both the English AND the French, the miss-understanding and the love-hate relationship between them.
Hortense, the alleged French author, is a caricature of a Parisian upper class woman, and her portrayal and silly (sometimes bigoted) comments are spot-on and hilarious. She's judgemental but endearing in her naivety and lack of understanding of the English, and the joke is on her. If you don't get the fact that the book is there to make fun of her, as much as being self critical of some aspects of English life, you would find some of her points outrageous, but that's precisely why they are funny.
French expats who have lived in the UK long enough to really get to know and appreciates its culture and its people, will enjoy reading this, because Hortense's candid remarks will remind them of the oddities they use to be puzzled with.
It has to be said that this book reflects the spirit of a time, and probably only applies from the 90's to about now. So I can understand that English expats living in France will not identify with any of it.
Equally I think French people who have only lived in England for a short while, will not get it either.
Also note that there is no French version of this book, it was not translated from French to English. I desperately looked for a French version until I realised that it only works in the English version. This is British humour and it doesn't translate ;-)
This is a niche book that will not appeal to the wider public, but I would think any long term French expat in England and vice-versa will be laughing from start to finish.