 Walter has enjoyed an extensive career in the theatre.She worked with the director Sam Mendes at the Donmar Warehouse in a production of Alan Bennett's "Habeas Corpus", was a member of the Peter Hall Company's production of "As You Like It" and featured in the National Theatre's revival of "Noises Off".In 2008 to early 2009 she spent a year as a member of the Royal Shakespeare Company (RSC), with leading roles as Helena in "A Midsummer Night's Dream" and Maria in "Love's Labour's Lost".