What's even more impressive: I really liked it. It was short -- well under 200 pages. Sophie (6) and her grandmother are the two protagonists. Grandmother's son and Sophie's father is in the background throughout, and a few other characters make occasional appearances. A series of vignettes, almost short stories, spread from April through August on the small islands of East Nyland, which is in Finland, but the characters all speak Swedish (this is in translation). There is a tremendous amount of detail about the little critters, plants, weather, boats, house and cottage, etc. Grandmother isn't well. Sophie's mother died at some point before the start of the book (as did grandfather, but the implication is that was probably before Sophie was born). Sophie's mother's death is handled even more elliptically than Bambi's mother's death: Sophie has a bed to herself because her mother died, which tells us that this family, like Swedish families to this day, enjoyed some form of a family bed.
Grandma, in her younger days, lobbied hard for children like her (girls) to be able to be Scouts, but didn't have her child(ren) be Scouts. One of the many entertaining episodes is when Sophie sleeps out for part of the night in a tent her Papa put out in case they had too many visitors and he couldn't stand it any more. When Sophie comes in for the rest of the night and chats with grandma, grandma is finally able to remember some details from her own sleeping-in-tents days, which she had been sad to lose in her memory.
Sophie's and grandmother's arguments are great: they're believable, rather than cute, and they provide a lot of suspense. What if something happened to one of them while they weren't getting along? And that's always a real chance, given grandma's frailty and the potential for falls, drowning and sudden storms. Sophie is always aware of death: she comes to hate small creatures because they die so easily, and when grandma helps her build a model Venice in the swamp and a storm wipes out a family there, Sophie responds as if her mother has died all over again.
I was reminded of Italo Calvino's _Invisible Cities_, in the structure of the book, and some aspects of the prose. But where Calvino gets a big bang out of a combination of a lot of abstraction with few well-placed details, Jansson's book is the inverse: a wealth of detail, and the odd juxtaposed abstraction. I sure liked _Invisible Cities_ when I was in college, even tho it hasn't completely stood up over the succeeding years. I suspect I'll just like Jansson more and more over time.