A couple of years ago I got these two books for my daughter:
We really enjoyed them. What is interesting is that they do not have main characters that are always succeeding, but trying very hard and putting a good effort into doing what interests them. Anyway, I came across this website article which recommends other others that we will definitely give a try (already have Matilda, Pipi Longstockings, and Anne of Green Gables) if we haven't gotten them already. https://www.goodreads.com/blog/show/1336-20-children-s-books-with-strong-female-characters?ref=book-show