Margaret Robertson (née Singer; 13 September 1916 6 February 1998) was a British script supervisor and personal assistant to Alfred Hitchcock from the 1940s to the 1970s during which time she worked on his films ''Under Capricorn'' (1948) and ''Stage Fright'' (1950), before joining his team permanently on ''Vertigo'' (1958), working thereafter on all of the director's remaining films.
Provided by Wikipedia