I spoke to Miss Betty yesterday, and the absolute word on Southern funeral attire is that it's not improper to wear open-toed shoes.
By observation, a woman can slso wear trousers without gathering ill-opinion.
Also, by observation, if you can can away with it physically, uncovered shoulders are fine, too. No sloppy, swaggy flesh, thanks.
That was in a Southern Baptist church in Vidalia.
I don't know about Natchez.