Mia's parents are divorced. Mia's real mother lives in Brentwood. Mia's father lives in Malibu, California with his new wife, Angela. Mia spends half of the year with each parent. Jack Johnson describes Mia as being the cutest girl at the school they attend, Malibu Middle School. Mia enjoys hanging out with Jack and Wilson Schlamme. Both boys constantly compete for Mia's attention.
Mia invites Jack and Wilson to her birthday party. At the party, Mia receives a CD from Jack. The music on the CD is by Purple Rose, Mia's favorite band. However, when Mia gets two tickets to attend a Purple Rose concert from Wilson, Jack storms out of the party in a jealous rage. Mia and several other kids chase Jack, but they fail to catch him.
Several days later, Jack offers to race Wilson, and Mia agrees to watch. Mia is shocked when, during the race, both boys begin flying. As she later finds out, Jack found a book that taught him how to fly in an abandoned house, and Wilson has borrowed the book from Jack without his permission.
As more people find out about their ability to fly, Jack and Wilson become increasingly more famous. This causes both boys to become so busy that they have very little time to spend with Mia. Eventually, Jack is scheduled to compete against Wilson in a race on national television. When the race begins, however, Jack doesn't take off. He seemingly can't fly!
Jack's life goes back to normal, and Wilson becomes so famous and busy that he has to leave the school he attended. Ultimately, Mia is happy because she gets to hang out with Jack again. Mia admits that she enjoys hanging out with Jack more than she enjoyed hanging out with Wilson.
Mia enjoys hanging out with Wilson and Jack. Whenever either of the boys impress her, Mia often exclaims, “Oh, wow!”
Mia is short, and she has straight black hair. She has green eyes and a petite nose. Mia is described by Jack as being very cute. Since Mia was born on Valentine's Day, she often wears heart-shaped pieces of jewelry.