Here is the full list of all 15 Nancy Drew: Warnings at Waverly Academy achievements.
Break more than a few rules
Be an avid photographer
Solved the case as a Senior Detective
Challenged Leela a lot
Obtained and held the high score in Double Take
Searched for that perfect book
Haunted the halls after hours
Tickled the ivories over and over
Solved the case as a Junior Detective
Found an Easter Egg
For working the snack shop more than most
Knock, Knock. Who's there? You!
Investigate the source of every rumor
When being a good student just isn't enough
You correctly answered the Trivia question