The coming of age of the Chalet School (by Elinor M Brent-Dyer)

(Amazon UK link) In my slow reread of the Chalet School books by Elinor M Brent-Dyer, I reached the one numbered 39 in the original hardback series published last century. I last read ‘The coming of age of the Chalet School’ towards the end of 2015, but it’s not one that I reread regularly. It was foreshadowed through a lot of the previous book, ‘Excitements at the Chalet School’ which I reread just over a month ago. 
This is the book where the Chalet School celebrates 21 years of existence. It wa...