Nancy's Mysterious Letter

The letter adds a personal touch to the mystery, but I wonder if Carolyn Keene had a specific message or theme in mind when crafting this plot device.

Her inquisitiveness is so contagious, but I’m curious whether the book’s pacing benefits from her relentless questions or if it could have slowed down.

Reading this brought back childhood memories of trying to crack clues along with her. Did others feel the same sense of adventure and innocence?