How well I recall seeing her in a revue in London called "Cowardy Custard." She performed the absolute best rendition of Sir Noel's "I've Been To a Marvelous Party" that I've ever heard or seen.
I'll second that. There is a YouTube performance when she was in her 90s, still gloriously over the top. I can't decide who owns this Noel Coward gem, Beatrice Lillie or Patricia Routledge. Oh, heck, I'm glad to have performances by BOTH .