It is a coming-of-age story set in a conservative, ultra-Christian family in Zeeland. The main character is precocious and full of life - and the persective she gives on life is a delight to read.
In my perspective, one of the most positive aspects of the story is that the focus given on Christianity isn't negative; despite not fitting into the family norms, there's still a sense that the main character is loved and cared for. And there's a sense that there are many good things about her religious upbringing, even if more freedom and a broader outlook on life would have been appreciated. In this way, the book besides being a coming of age story is also a book that gives a positive glimpse into the life of a fairly closed group, which is often misunderstood by those not holding to the same conservative Christianity.