The top mistakes in I Know Where I'm Going! http://www.moviemistakes.com/film4075 en Sat, 29 Nov 2008 06:55:19 +0000 53182 This is not an error in the film itself, but in some supplementary material on the DVD, in which Margot FitzSimons, the actress who plays Bridie, is identified as the sister of Maureen O'Sullivan. She is in fact the sister of Maureen O'Hara.