ALICK. What IS charm, exactly, Maggie?

MAGGIE. Oh, it’s — it’s a sort of bloom on a woman. If you have it, you don’t need to have anything else; and if you don’t have it, it doesn’t much matter what else you have.

James Barrie (1860-1937) Scottish novelist and dramatist

What Every Woman Knows (1918)

Usually quoted in an elided format ("Charm, it's a sort of bloom on a woman ...:).