Annie is the main character of BrainPOP Jr, along with Moby. She and Tim are the only people who can understand Moby, along with Ben. Annie has a sister named Mia who talks on the phone too much. Her best friend is Becca and she is in Mr.P.'s class.

It has been strongly hinted that Annie is Mexican as her dog's name is Sr. Maurices and she sometimes refers to her father as "Papi".

Annie is allergic to eggs and when she is angry, her face turns red.