With new kin discovered on each season of ''Alias,'' Jennifer Garner's Sydney Bristow has the fastest-growing family on TV. The latest newly unearthed member of the Bristow clan will be Sydney's sister, to be played by Argentinian actress Mia Maestro, according to the Hollywood Reporter. Maestro will appear in the final three ''Alias'' episodes this season and will return in the fall as a regular, according to the Reporter.
In 2002's ''Frida,'' Maestro played Christina Kahlo, sister to Salma Hayek's Frida. She also appeared in this year's ''The Motorcycle Diaries,'' and co-starred with Hayek again in the 2001 Showtime film ''In the Time of the Butterflies.'' Certain ''Alias'' fans might also be interested to know that Maestro made men's mag Maxim's 100 Sexiest Women list in 2001.