Rachel McAdams is Irene Adler

Rachel McAdams bundles up and keeps warm with a steaming hot cup of coffee while shopping with a gal pal in London on Monday.

The 30-year-old Canadian actress has been in town to film Guy Ritchie‘s detective flick, Sherlock Holmes. She plays leading lady Irene Adler, a femme fatale from New Jersey who once outwitted Sherlock (Robert Downey Jr.), earning his grudging respect. Last week, the first pictures of Rachel — in hair and make-up as her character — popped up online.

Sherlock Holmes is expected to release October 2009.

10+ pictures inside of Sherlock star Rachel McAdams…