She began acting in Hong Kong and elsewhere in East Asia. Because of her non-Chinese heritage, many of her Asian film appearances are in English or dubbed in Chinese languages. She has, however, stated that she took Mandarin and Cantonese lessons during her career in Asia and is able to speak both languages in varying degrees. Among her first appearances in film was the lead roles in the Hong Kong action thrillers Gen-Y Cops and Naked Weapon, in which she played the sexy but vulnerable martial artist assassin Charlene Ching. She has also played the titular role of Harmony in the German-Singapore telemovie collaboration Das Haus Der Harmonie, opposite leading Singaporean actress Fann Wong.

In 2006 she starred alongside Tom Cruise in Mission: Impossible III. She played Zhen, the only female member of his IMF team. Maggie played Mai Linh, one of the computer-hacking extortionists in the 2007 Bruce Willis movie Live Free Or Die Hard, the fourth film in the Die Hard franchise. On A