I used to think 'potted meat' sounded so exotic in the midnight feasts!
Summer, I think it's also that there's a very highly-developed adult 'fan culture' around the Chalet books - there used to be (maybe still is?) a fan site called the Chalet Bulletin Board for discussions and fanfic, which had a huge membership, and meet-ups and bookswaps, and there is/was a Chalet fan magazine. If you like discussions and aren't already on there, Google the CBB, if it still exists.
The 'invisible' pregnancies - despite the intense interest in which old girl can have more babies, and the bizarre 'larger family' rivalry - used to crack me up, too. Joey spends a weekend with Madge not long before she gives birth to her first child, and apparently Madge tries to hint to her, but Joey is oblivious, and when Madge has a bad time during the birth and Joey is called up to see her, apparently the whole thing comes as a total surprise.
And Joey herself has two teenage CS girls living with her throughout her pregnancy with the triplets, and neither of them appear to notice a thing, when there must have been indiscreet triple-foetus bulges going on all over.
In the franker, later books, you do get references to Joey not being able to take on something because she's going to be 'busy', nod, wink etc. And occasionally there is much Significant Knitting of Tiny Matinee Jackets.