Imagine my joy when I stumbled across a Ray Bradbury story I've never read (and I thought I'd read them all!) The story is called "The Trunk Lady", and apparently is quite rare (having never been anthologized to my knowledge in a RB collection). I found it in an old paperback, HORROR TIMES TEN, while sifting through old books at home. I look forward to reading it tonight!

Yes, it's been anthologized, in the collection you found, and probably others. It was also collected in the rare Bradbury volume "A Memory of Murder."