I contacted the Duplin County Register of Deeds to find out that they actually have their records online. What a nice surprise. So I immediately logged on and searched for my mother's paternal grandmother.
Once again, I was completely disappointed. Annie M. Darden/Derden was not listed among the deceased in Duplin County. It's as if she disappeared after the 1920 Census. I am not sure exactly how to proceed here. I know that her father's name was John, but that is a very common name. I know that he was related to another John Darden and a Jack Darden. But I have been told they were cousins. I have found Jack Darden and his family on the census. I'm thinking that perhaps I should find Jack again and see who's living near and around him. Maybe I'll find something interesting.