I adore the Chalet School series for many reasons. It is a long running series- the first book, The School At The Chalet, was published in 1925; the final one, Prefects Of The Chalet School, in 1970. The New Mistress At The Chalet School is a later book, published in 1957, when the school is based in Switzerland post- World War II.
One of the features I have always enjoyed about the books is that while there is always a protagonist (Joey Bettany in the earlier books, a variety of characters including Daisy Venables and Bride Bettany in novels set in Guernsey and Wales during and immediately post World War Two and Mary-Lou Trelawney in many of the Switzerland ones) there are often multiple points of view. In New House at the Chalet School (1935) this included an unsympathetic new Matron. However New Mistress is in my experience unique, as the protagonist is a teacher, although there are multiple points of view.
Kathie Ferrars has just completed her degree, and her post at the Chalet School is her first teaching job. Her own school was a day school rather than a boarding school, so she is unprepared for the different staff- pupil relationship of boarding school life. She seems a little young for her age, still very reliant on the approval of her uncle and aunt who brought her up; in the first chapter she kneels on the carpet with her head in her aunt's lap (frequently an attitude of repentance of the school girls in Chalet School novels), and her aunt advises her that she needs to maintain her dignity with the girls. We are told at the end of chapter 1 that this advice is a source of some trouble for Kathie in the future (Brent-Dyer does like a foreshadowing authorial voice!)
The journey to the Chalet School (involving trans- European train travel) is mostly explained through food- American chocolates, French patisserie, breakfast in Basle including Swiss jam- must have been extremely exciting for readers, as rationing had finished only in the early 50s- my mother read these books well into her teens, and I'm sure this was the case with other readers. Memories of the shortages of cream, sweets, cakes and jam would have been still vivid.
Kathie makes friends among the other teachers, and takes advice on her new class- Inter V, girls who are either too young to be seniors (such as the incredibly fertile Joey's triplet daughers, Len, Con and Margot) or whose academic work is not up to the standard of the girls of their age, such as new girl Yseult Pertwee. All the features of the Chalet School education- tri-lingual in English, French and German, European in outlook, care of the girls' health and physical needs by abandoning the timetable and getting out into the fresh air for climbing, walking and skiing in the right weather- is established through explanation of the routines to Kathie, which felt natural- also making this book a good one to start with if you're not familiar with the series.
Conflict comes very quickly with Mary-Lou Trelawney, a prefect in this book. Mary-Lou is an interesting character. After her arrival in Three Go To The Chalet School when she is 10 Brent-Dyer is clearly enamoured with her informal way of addressing people (we are often assured that it is not "cheek") and her easy- going character, but I find her bumptious and irritating, and find it hard to believe that she would be so un-self aware at 17 or 18, particularly in a school where character is so important. Kathie finds her so to begin with, although after Mary-Lou has saved her from certain death in a crevasse of a glacier, she starts to think differently (as you would!)
Kathie makes other mistakes with discipline, but starts to loosen up after her accident, using her judgement to re-think her punishment of Margot for lighting a sparkler in prep that would have resulted in her missing part of her birthday treat. However she continues to misjudge situations, resulting in new girl Yseult breaking her collar bone in a skiing accident after she tries to take out Mary-Lou, whose part in the Christmas play she is understudying. While the Chalet School is very forward thinking in many ways, in particular in the thematic approach to the curriculum, with an emphasis on thinking and understanding rather than learning facts by rote, the class conscious comments (for example about Joan Baker's permed hair) and disapproval of any parenting views out of the middle class norm (such as Mrs Pertwee's) are still in evidence (I wrote about this here).
This is a fascinating book. Not one of the most exciting plot-wise, maybe, but the only one I can think of where a teacher's first steps into professional life is depicted in a story for young readers.