Thanks, @PhoebeSnow, I love that film, and am also a huge fan of Audrey Hepburn. Grim old day here, so wasn't going to go out, and now I can settle down on the sofa with the divine Audrey!
I'm not a Catholic or high Anglican, so have little experience of nuns, but there are so many good dramas with nuns as central figures. Black Narcissus, The Nun's Story, The Sound of Music, Derry Girls, Call the Midwife - there must be more. They feature in Father Ted here and there too, of course, and there's a significant supporting role for a nun in The Lady Vanishes (the classic 1930s one with Margaret Lockwood, Michael Redgrave and Dame May Whitty - I love that film). Good Omens, The Omen. Never seen Sister Act.
I was trying to remember the name of a film I saw years ago which paralleled Watergate but set in a convent. It must be Nasty Habits, starring Glenda Jackson. Can remember very little about it except feeling that it should have been funnier, given the splendid cast.