The eldest of three children, Popplewell began acting at the age of six, taking classes at the Allsorts Drama School. She began acting professionally in the TV production Frenchman's Creek in 1998. She made her film debut in 1999 in the film Mansfield Park and in 2000, Popplewell received her first breakthrough role in the childrens film The Little Vampire. In 2002 she appeared with Stephen Fry, Simon Callow and Rupert Grint in the comedy Thunderpants. Popplewell was next seen in the critically acclaimed film Girl with a Pearl Earring with Colin Firth and Scarlett Johansson.

--Wikipedia