The building for Lavender Lawns where the nuns ghost is reported is the same location used in Turn Left (2008) for the raffle ticket vacation resort.
Mrs Randall remembers seeing The Gorgon (1964) with Christopher Lee and Barbara Shelley. The film also stars Patrick Troughton, the actor who portrayed the second incarnation of the Doctor in Doctor Who (1963), and Peter Cushing, who played Dr. Who or "the human Doctor" in Dr. Who and the Daleks (1965) and Daleks' Invasion Earth 2150 A.D. (1966).
Sister Helena makes a threat about "solving a problem like Maria." This is especially amusing coming from a nun, as it's a reference to a song the nuns sing in "The Sound of Music."