Musician, dancer, and actress Mía Maestro studied the arts in Argentina until the age of 18, when she moved to Berlin for further vocal training and was able to add the works of classical German composers to her singing repertoire along with further acting and dance experience. At 20 years old, Maestro traveled back to Buenos Aires, where she won an ACE award for her performance in a theatrical production of Pandora's Box. In 1998, she made her feature-film debut in Tango, in which she played an aspiring dancer who becomes entangled in a romance with a film director. Just one year later, Maestro traveled to Austria, where she was able to work with Lauren Bacall and Dennis Hopper in The Venice Project (1999). Ultimately, however, she would move to Los Angeles and shortly thereafter earn a supporting role in Timecode (2000) alongside Salma Hayek, with whom she would work again in 2002's Frida. In 2003, Maestro was able to play a much larger role in Walter Salles Jr.'s road movie The Motorcycle Diaries, which premiered at the 2004 Sundance Film Festival. After a small role in Ben Stiller's Duplex (2003), Maestro accepted another supporting role in Lucrecia Martel's coming-of-age drama La Niña Santa (2004). Also in 2004, Maestro appeared in a recurring role on the popular television spy drama Alias, playing the newly discovered younger sister of main character Sydney Bristow (Jennifer Garner).