I could find you ten chicks that sound like either of those characters. Everybody in Memphis doesn't talk like that but walk around any public place and you'll find some chicks that talk like that.
The Memphis accent has evolved since Southern rap started becoming more mainstream because cats are trying to represent the south by exaggerating their accents these days. I blame Nelly, who ironically, isn't from Memphis. But before he hit it big, everybody I knew from St. Louis (all three of them I went to TSU with) talked like they were from Chicago, while the Memphians rolled their R's and put R in any word that started with a U. A lot of people do that shit on purpose down here. If you spend enough time here, you'll do that shit too.
"...most sistahs only recognize a good man when he's a character in a shitty movie, a shitty play, their favorite daytime soap or a shitty book written by a homosexual."
From Reggie Eggert's online review of "Diary of a Mad Black Woman"