3.5 stars.
Read the original edition from the 1950s. I'd love to see the new art in the one by the Dillons.
I could probably only really describe this book's story as "quaint" and "cute," but boy is the writing top-notch. It really elevated the story from "twee fairytale defying all logic" to "enjoyable story of minor adventure and childhood wonder." I fully believed in Calpurnia as a character, though no reveal of her age made it hard to decide whether I bought her precocity. All in all I think it's a nice little Newbery Honor book unjustly overlooked.
(Time to go read The Yearling and be sad Rawlings never wrote anything for kids besides The Secret River, I guess.)