Sienna Miller is used to playing a gentle, doe-eyed love interest - but she sure is toughening up.

The 26-year-old began shooting her new Hollywood film GI Joe in Los Angeles yesterday, in which she plays the villainous Baroness - a femme fatale skilled in espionage.

She filmed a funeral scene yesterday, where she was seen carrying a folded American flag and spent the breaks between takes texting on her mobile.

The actress is rumoured to have gained 5lbs and has started an ...