Robin's mum died of TB and everyone was scared she'd get it as well (though they weren't like that about the Lintons), and she was a bit sickly as a child.
Joey Goes to the Oberland is a weird book. It's definitely one for the hardcore fan. It was one of the first CS books I read and there were a lot of allusions to past books, plus it was basically Joey travelling around Europe with her 8 kids and Daisy's little sister. If you were new to the series you'd be thinking, "WTF is this? Who are all these people?" And Frieda should have bitchslapped Joey into infinity for her oh-so-charming nickname for Carlotta.
I've actually been to Oberammergau and it's just as the books say, though I didn't go the Passion Play (it was supposed to be last year, but COVID happened). It's very pretty, lots of wooden chalet-type buildings with religious murals, and the scenery is gorgeous.
I do snark the books a bit, but I genuinely love them. I wouldn't read them if I didn't. The Tyrol/war books are the strongest, Eustacia aside, and I actually like the St Briavel's ones as well because they have a strong cast. There is a lot of Mary-Lou, but she's younger, has Verity (before she develops a personality transplant) and Clem to rein her in and actually gets told off when she's obnoxious. The Swiss books are a mixed bag. They're very formulaic and because each book is set in a different term, they're more compressed and you end up with Len being Head Girl for about 6-7 books and she just isn't a strong enough character to carry a plot like her mum or Mary-Lou. This was also when EBD was getting super-Catholic and conservative to boot - the speech about beatniks was her talking, not Joey. Joey used to be a scruffy little thing and the books always talk about how messy she is, she's not in a position to claim that being untidy means you can't be trusted, or have a go at Ruey and Ted for not being pretty enough. Just like Miss Wilson's incredibly cringey speech in Camp about how every woman should be a good little housewife and how emancipation is a load of rubbish. It sounds so off coming from an unmarried science teacher. It also explains things like the prayer circle in Triplets. EBD wasn't interacting with girls by then and she was very out of touch. Girls in the Chaletverse were still putting their hair up at 18 and only listening to folk and classical music, even in the late '50s.