There are 13 books in this series. We are starting with book two (because we don't have book one) and the three girls are 8 years old -- just like Laura. It's amazing how much more interested kids are in books when the heroine/hero is their exact age or something else about the story matches up exactly with something from their own life.
Lovelace wrote very autobiographically in these books and they are set in a small town in Minnesota. Although they were written in the first half of the 20th century, the books still remind me of my childhood years in a small Pennsylvania town. I can't wait to re-read the entire series!
Please note this post contains affiliate links.