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?
Base Breaker: the Swiss era. Some fans like the books and the new characters, while others feel the series went down the pan around this time. See Jumping the Shark below.
Most Chalet School books written by other authors after EBD's death, such as Peace Comes to the Chalet School, have been received favourably by fans. The Chalet Girls Grow Up, however, is an exception. Some fans love its Darker and Edgier nature, while others think it's downright horrible, and a mockery of EBD's work.
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 - who could 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.
Growing the Beard: the wartime books, particularly Exile, Goes To It and Highland Twins, which are believed to contain some of EBD's best and most powerful writing, not to mention that the idea of separating Germans from Nazis - see the entire Peace League plotline, and the more sympathetic German and Tyrolean characters - was pretty ahead of its time. Characters such as Verity-Ann Carey and Lavender Leigh who make nasty remarks about Germans are called on it by other girls, particularly the ones who were with the school in the Tyrol.
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.
Lavender Leigh is a horrible little brat, and like Eustacia, her preciousness and habit of grassing the other girls up makes her unpopular, but it's hard not to feel sorry for her when all the other girls in her form - even the nice ones like Peggy and Bride Bettany - make a huge point of ignoring her for days, and she spends most of her time feeling lonely and miserable and crying herself to sleep. As someone who's been carted around the world by her ditzy aunt, she's not remotely used to being with kids her own age and has no idea how to behave.
Naomi Elton may be guilty of Disability as an Excuse for Jerkassery in Trials, but as she reveals to Mary-Lou, she's got a good reason to be bitter and have little faith in G-d. Her parents were killed in the same car crash that disabled her for life, and she had to give up her dreams of being a ballerina.
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.
Jack Lambert is disliked by some fans due to her bullying of Jane Carew, obsession with Len and general Alpha Bitch behaviour, especially given the possibility that, had the series continued, EBD would have made her the new heroine after the triplets left.
Reg Entwistle, for his unromantic proposal to Len Maynard in Prefects, and for coming across as quite possessive of Len, which may have inspired his less-than-favourable portrayal 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.
Take That: Lavender Leigh and the Lavender Laughs travel books may possibly be one to Christopher Robin and AA Milne.
They Changed It, Now It Sucks: the Armada abridged versions get this treatment, due to cuts being made by the publishers. While some changes were positive, such as getting rid of the Funetik Aksents of characters such as the McDonald twins, some books had important plot elements missing. In some books such as Highland Twins and Ruey Richardson, Chaletian, entire chapters were cut out of the books. Girls Gone By Publishers remedied this by re-publishing the unabridged books, albeit without EBD's typos.
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."
What Do You Mean, It Wasn't Made on Drugs?: Althea Joins the Chalet School is one of the odder books in the series. Len getting covered in paint! A pink worm in an engine! Dreams about monkeys on ships and being chased by scary black men with red lips and swords! A burglar stealing shoes! As one fan said, "some of the dreams in this one suggest EBD had been at the magic mushrooms."
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.