Why translate the title of a movie?
I was working on an article about an actor. It said something like .... this actor started his career with the film La Dame de Windsor... so I translated the whole thing except the title of the film. my answer was the same as the top answer except that he wrote The Dame of Windsor. Am I right or wrong here?
I think in case of movie or book titles and the like, it's best to do a little bit of research and substitute the official English title. So, in your case I'd vote for 'Mrs Brown', particularly since the original version was in English.