In reading order
Naughtiest Girl in the School
Enid Blyton
The Naughtiest Girl: Naughtiest Girl Again
Enid Blyton
The Naughtiest Girl: Naughtiest Girl Is A Monitor
Enid Blyton
The Naughtiest Girl: Here's The Naughtiest Girl
Enid Blyton
Naughtiest Girl Keeps a Secret
Anne Digby
The Naughtiest Girl: Naughtiest Girl Keeps a Secret & Naughtiest Girl Helps a Friend
Enid Blyton, Anne Digby
The Naughtiest Girl Helps a Friend
Anne Digby
The Naughtiest Girl Saves the Day
Anne Digby
Well Done, the Naughtiest Girl
Anne Digby
Naughtiest Girl Wants to Win
Anne Digby
The Naughtiest Girl Marches On
Enid Blyton, Anne Digby