Twenty-five years have passed since we last visited the six Walker sisters from Memphis, Tennessee, and they're all back on the phone again for another crisis-filled weekend. The most immediate concern: Mama has taken off all her clothes in the community room of her nursing room and the sisters must put their heads together and decide what to do with her. And that's just for starters: oldest sister Peggy has been bilked out of all her money by a ne'er-do-well boyfriend. Aneece and Paige's marri