These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
The Chalet School itself: the school every girl would have dreamed of going to, or a repressive, ultra-conformist Crapsaccharine World?
Double Standard: The contrasting way certain characters' attitudes to men are handled, probably because of their backgrounds. Nice Christian girls Marie and Frieda talk about getting married and having babies? Perfectly OK. Sweary, fish-and-chips-eating, working-class Joan Baker talks about 'boys' to the other girls? She's clearly some kind of corruptive influence and it's perfectly fine for Mary-Lou Trelawney to pretend to befriend her while actually planning to reform her.
Speaking of Mary-Lou, there are arguably some major double standards applied to her in-universe. She can be as cheeky as she wants to the teachers because it's her way, but you get the impression other girls wouldn't get away with the same thing. Also, 'sneaking' is considered a crime in the Chalet School - Miss Wilson tells Eustacia where to go when she tries it - yet there are no repercussions when she runs off to the Maynards to talk about Joan Baker in Problem for the Chalet School.
It's doubtful whether any girl outside the MBR families would not have been expelled for knocking Betty Landon out with a bookend. Thekla von Stift is expelled and told that had she caused Mrs. Linton to worry by getting Joyce Linton into trouble, Mrs. Linton could have died and she could have been a potential murderess! However, Margot - whocould have easily killed someone - gets off with a ticking-off from Miss Annersley and not much else, and Betty is blamed for being 'tactless'!
Ensemble Darkhorse: Gaudenz, the school handyman who appears in the Swiss books, has his fair share of fangirls.
Fan Nickname: 'OOAO' for Mary-Lou, short for 'Our One And Only', 'MBR' for the Maynard / Bettany / Russell families, and 'EBDisms' for the author's various plot holes and inconsistencies.
Glurge: To the more cynical modern reader, some of the books can come across as immensely glurgey, particularly the ones with heavy emphasis on religion.
Jerkass Woobie: Grizel Cochrane, the resident Broken Bird. Yes, she can be a real bitch to the younger and less cynical kids, and a lot of the pupils are scared of her when she becomes a teacher, but she has a terrible relationship with her father and stepmother, and suffers some pretty nasty injuries throughout the series. Plus she never wanted to be a music teacher in the first place and only trained as one because her father would have cut her off otherwise.
Jumping the Shark: For many fans, the Swiss books are among the weakest of the series, especially compared to the Austrian books.
Kathie Ferrars and Nancy Wilmot are a popular pairing in Chalet School fandom. In The Chalet Girls Grow Up, a couple of characters even speculate that the two are more than friends.
Purity Sue: The Robin starts off as this, but grows out of it. Joey kind of ends up as this.
The Scrappy: Mary-Lou is disliked by a good few fans for being a self-righteous goody-two-shoes (particularly when she's a prefect), and getting away with talking smack to the teachers because 'it's not cheek, it's Mary-Lou' (see Double Standard above). It doesn't help when EBD makes Kathie Ferrars look like an unreasonable bad guy when she - quite understandably - has a problem with Mary-Lou's over-familiarity in A New Mistress at the Chalet School. Merryn Williams evidently hated her, judging how she made Mary-Lou behave towards Len in The Chalet Girls Grow Up.
Stay in the Kitchen: Usually, when any serious problems come up, the female characters have to stand aside and let the male characters take over. Particularly jarring when you consider how few male characters there are compared to female ones.
Girls are expected to give up their jobs once they marry and become housewives. For instance, one character, Julie Lucy, is a barrister, and when she gets engaged, another character remarks that she'll have to give it up as she won't have time 'as the wife of a housemaster'.
Men's job is to protect their daughters and wives, and the female characters are always deferential to them, even the headmistresses (to Jack, Jem and the other San doctors). EBD also seemed to equate feminism with hating men, if Joey's comments in The Chalet School Reunion are anything to go by.
The 'feminine' subjects appear to get more emphasis than traditionally more masculine subjects, such as maths and science. Girls are expected to be proficient in subjects such as cooking and sewing, so that they will make good wives (see above). Joey gets no end of flak from the Tirolean girls about her failure at sewing.
There's a heavy emphasis on obedience and religion, especially Catholicism, and one girl shocks her peers by saying that she is an agnostic. Needless to say, she's convinced into believing in G-d after an avalanche.
And then there's the racism - for instance, Joey's comment about her sons, who have been messing around with blacklead, looking like 'two little nigger boys' in Joey Goes to the Oberland, and Robin talking about Daisy 'working like a nigger'. Not to mention some of the girls in Rivals of the Chalet School starting up their own branch of the Ku Klux Klan, after reading books about them, in order to get back at the St Scholastika's girls.
What an Idiot: Someone should have told Miss Ashley in A Feud in the Chalet School that when a much-loved art teacher dies, and you're with two members of staff who are clearly very upset about his death, the appropriate response is not something along the lines of "Oh, he's finally dead, that means St Hilda's can have his house."
The Woobie: Try reading Gay from China and not wanting to give poor Jacynth Hardy a hug by the end of it. Especially when she finds out about her auntie going in for a serious operation, and then dying. She gets better, with help from Joey, Miss Wilson and Gay.