Not that there isn't problematic stuff in them, they are books about pre-WWI 20th century Minnesota, written in the 40s and 50s. But it's a lot less than other kids' and youth books about American old timey stuff – way less minstrelry, Manifest Destiny, and racism against indigenous people than Little House On the Prairie and that kind of pioneer story.
Also to compare them to another series of a nearby time period, Betsy grows up but the books don't get dark like the Anne of Green Gables ones do. (There's understandable and sympathetic reasons for that and the Anne books are richer stories, but still...) It might be best to say that Betsy and Co. get to kind of stay in the Anne of Avonlea/of the Island period where it's mostly about the joy of new experiences and community.
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