- David Gordon: "Freaky, huh?"
Lizzie McGuire: "Way freaky."
Isabella Parigi: "Way, way freaky."
- —Gordo, Lizzie and Isabella, as Isabella shows herself to Lizzie
Role in the film
Before the movie, Isabella and her then-singing partner and boyfriend Paolo Valisari were supposed to present an award at the International Music Video Awards. They had a falling-out, and Isabella left him. It was then that Paolo then decided to take matters into his own hands.
When Lizzie McGuire and her graduating class are taking a tour to Rome with their future principal, Miss Ungermeyer, and Lizzie strays away from the group to the Trevi Fountain, she meets Paolo, who notices how much Lizzie resembles Isabella. Paolo and Lizzie agree to meet at the Trevi Fountain the next day.
Soon, some of the media catches them together, and the tabloids mistake Lizzie for Isabella with dyed hair (Lizzie is a blonde, and Isabella has black hair), which is apparently part of Paolo's plan. Lizzie discovers she must lip-synch the hit song "What Dreams Are Made Of".
Soon, Miss Ungermeyer discovers a student has been skipping, and Gordo willingly takes the blame. Cut out of the class, Gordo heads to the airport where he runs into the real Isabella, who saw a tabloid featuring Lizzie's picture, demanding an explanation. It is revealed that Paolo's plan was to make it seem that Isabella is lip-synching, and in doing so, avoid getting sued for breach of contract.
During the concert, Gordo and Isabella race to the IMVA, being held in the Colosseum, to stop Paolo from making a fool out of Lizzie on stage. The two reach Lizzie just in time to convince her of the truth. While Paolo and Lizzie sing their duet, Isabella and Gordo expose Paolo by pulling the plug on his record tape and turning on his microphone, causing him to be shown as the fake he is.
Isabella then introduces her new American friend Lizzie McGuire to the audience, and they sing an upbeat of "What Dreams Are Made Of", before Isabella then leaves Lizzie to sing on her own. Lizzie tries to run off, but Gordo tells her that she can do it, and she does a great job. Isabella is last seen when she joins Lizzie in and they bow to the audience.