Amelia

Amelia is Daphne Davis' cousin. She doesn't appear in the books, but on the back cover of every book, a word bubble is shown with Amelia saying:

"Hi! It's me, Amelia. You'll love my cousin Daphne. I hope Daphne will let me be part of her diary soon!"

- Confirmation of Amelia being Daphne's cousin

Behind the scenes

 * Amelia is the star of the series, Amelia's Notebooks. Daphne's Diary of Daily Disasters is a spin-off to the Amelia's Notebooks series.
 * According to Marissa Moss she plans to have Amelia appear in one of Daphne's diaries soon.
 * Daphne's Diary of Daily Disasters was advertised on one Amelia book.