I really need to be better at bookmarking things I see online and might want to refer back to. Someone blogged about this book, after finding it in a charity shop (I think) a couple of months ago. It sounded like fun and there was a cheap copy on Amazon marketplace so I got it. It's every bit as much fun as it sounded but I can't find the original post I saw, and I haven't found out much about 'Petronella Portobello' either, beyond that it was a pen name for Lady Flavia Anderson.
Lady Flavia was the daughter of an earl, married a Scotsman with a castle, wrote books under her own name as well, and had two sons. Petronella, the Deb's mum, has a daughter, writes book reviews to make ends meet, and is a widow living in a draughty pile in Scotland. This book is a humorous (I'd say it was more good natured than the word satire suggests) account of launching a daughter into society by someone who was clearly an insider.
It's the good nature that makes it so appealing (there's non of the spite that I associate with Nancy Mitford, for example, who never seems quite as U as she might have liked). The sense is that this is someone who's laughing at herself rather than mocking others, and in the process has created a curious historical document that has the added bonus of being very funny.
As far as I can tell from all the googling this is a fairly accurate portrayal of what doing the season looked like by the mid 1950's (published in 1957). Our Deb's mum isn't hugely well off; it's a visit to her trustee and the revision to dip into capital to pay for her daughters season - so why do it?
The answer to that seems to be partly because it's what has always been done, it's a right of passage, partly because it's fun, but mostly for the networking opportunities it brings to meet other suitable girls. The argument seems to be that for the majority of these girls there isn't enough money for them to sit around waiting to be married - it'll be jobs all round the following year, and until a suitable husband does turn up. When he does, he probably won't be so very wealthy either, so it'll be a life of trying to make ends meet, the roof in one piece, and the linen in good enough order to keep up appearances before visitors, whilst quietly flogging the family portraits. After a few years of which, when the honeymoon period is over, a network of friends to fall back on is vital.
There's the gentle observation that 'good' girls schools were not on the scale of boys schools, so the chances of making a wide circle of friends was limited. Being a debutante provides the opportunity to meet others from the same background who might be neighbours, might marry a man who could help with a thing, will be useful hostesses for your own daughters one day - all of it.
Which is interesting, but a better reason to search out this book, or pick it up if you spot it somewhere, is that it's funny and charming. I'm actually slightly surprised that it hasn't been rediscovered/reprinted by someone, we're very much in The Provincial Lady, or D. E. Stevenson's 'Mrs Tim' territory, with hints of P. G. Wodehouse. If you like any of those this is safe ground.