The native New Yorker moved to Los Angeles for college but almost gave up acting because of the strenuous and physical demands in Hollywood. But things changed after Spiro was hired for a part on the show Maybe This Time in 1995. Spiro continued with anonymous TV guest spots until she landed a regular role playing Annette O'Toole's daughter on the action-adventure series The Huntress. In 2005, she turned heads with a scene-stealing performance as a dull-witted party girl in the big-screen romantic comedy Must Love Dogs. The next year, Spiro snagged her breakthrough role as a sports writer/tomboy looking for love on the sitcom My Boys.