She was born in New York City in the United States, although raised in Paris where she started acting at the age of 10.
In 2004 she took her career to an international level; working in films and television in the US, and in the UK in 2008. She appeared in the 2009 film 2012 as Tamara.
She played a role in the eighth season of the WB series Charmed as innocent Maya Holmes as Piper Halliwell's first new identity. She appeared in the fourth season of the WB series Smallville as Dawn Stiles, a girl who wanted desperately to be prom queen. She also portrayed Gabrielle la Claire, daughter of the French ambassador in the 2004 film Chasing Liberty, and Natascha in The Dark Knight opposite Christian Bale. She appeared in Sharpe's Peril, the latest installment of the popular Sharpe series, starring opposite Sean Bean in 2008.
Rosen will appear in David E. Kelley's upcoming legal drama Harry's Law, which is expected to air on NBC during the 2010-11 television season