Continuity mistake: In the first two seasons, there are 3 bedrooms upstairs: Mama's, Fran's, and Sonja's. But after Buzz and Sonja move out and Aunt Fran dies, Bubba moves in and takes Aunt Fran's room. Vinton and Naomi are still in the basement complaining that they wanted Fran's room. However, originally there was another room upstairs, Sonja's room, that disappeared.
Continuity mistake: When Vint moves in, he stays in the basement. Mama, Fran, and Buzz all have a "bedroom." Sonya moves into Fran's studio. Then when Naomi thinks she's pregnant, they argue over where Vint and Naomi will move to instead of the basement. Fran says she won't give up her room, Buzz says his room is in the attic. Sonya says her room is microscopic. Thelma has the biggest room. Then on Mama's Birthday, she gets Buzz to help clean out of the attic, which obviously wasn't his room as he stated. Then, of course, after Buzz, Sonya, and Fran are all gone there's only room for Thelma and Bubba upstairs.
Plot hole: As Mama tells Iola about the April Fools' jokes the family has played on her over the years, Iola expresses surprise. Considering Iola has been Mama's friend for years and is constantly at the Harper house, it seems impossible that Iola had never heard of any of the April Fools' pranks.
Character mistake: When it is announced that Mama's block has been chosen for the new city dump, Iola states that she would have to move too. Being that Iola lives across the street she does not live on the same block as Mama and therefore would not be affected.