This is what happens when you don't do your googling before posting
an overview of a subgenre. You have to do a follow-up post.
Here's an informative overview of the Sally Baxter series.
Article:
Not Just for Children Anymore: Girls' Series BooksWhat many girls' juvenile series seem to have in common is that they posit the existence of a safe, orderly world, a world where right and wrong are clearly defined, and where right eventually triumphs. The protagonists face dilemmas, but few moral ambiguities. They are secure, fulfilled, and happy--and they never forget to be "feminine," to act like ladies, even when they are being their most adventurous and liberated.
More info on this subgenre at a comprehensive site - it has info on the Susan Sand mysteries (I have three of them).
This is the related blog.
The Cherry Ames page.