- “I look like Stevie Nicks.”
- ―Anna in Tess' body
Anna is a 15-year-old high school student who appreciates sleeping in late, fashionable dressing, and her punk rock band. Her mother is Tess Coleman, who is a hard-working psychologist and writer that gets by with a collection of cell phones. She also has a little brother named Harry, who annoys her very much, especially when he enters her bedroom. Despite this, she still loves and cares about him. She (in Tess' body) is incredibly touched by Harry's paper about how much he secretly loves her.
Anna dresses in punk attire, usually with the colors red and black. She has dirty-blonde hair, fair skin, and wears a navel piercing she hid from Tess before they switched bodies.
Anna is apparently herself in the beginning and the end. She argues with Tess a lot. One night when she, Tess, Harry, Alan, and Ryan, go to dinner at Pei Pei's Chinese Restaurant, Anna and Tess get into an argument. Pei Pei's mother comes with two fortune cookies, and as they open them, there is an earthquake only they feel.
The next morning, Anna wakes up in Tess' body. It happens that Tess woke up in Anna's body. They go back to Pei Pei's to see what happened. Until they get switched back into their own selves, they must do each other's positions. Anna goes to work as a psychologist. She is later being interviewed for a psychological book that Tess wrote. It is being filmed, and is on TV at her school, which embarrasses Tess.
At Anna's band rehearsal, Tess does not know Anna's performance; she does not even know how to play the guitar. Anna plugs in an electric guitar backstage for Tess. After the rehearsal, Tess realizes that Anna's band is way more fun then she thought.
At the end of the film, there is one more earthquake and Anna and Tess are switched back into their own selves. Anna performs at Tess and Ryan's wedding.
- Before Lohan was cast, a few other actresses were considered for the role.
- Originally Kelly Osbourne auditioned as Anna and was offered the part, but decided to back out. Later, she said people told her it was the biggest mistake she had ever made, due to the success of the film.
- Michelle Trachtenberg was cast as Anna, but had to back out, due to her contractual obligations to Buffy the Vampire Slayer (1997).
- Anna's guitar is a custom Fender Jim Adkins JA-90 Telecaster Electric Guitar in Crimson colors.