Audio problem: At the end of the film, where Big Momma is performing with Carrie's cheer leading squad, when Andrew breaks loose and climbs up the human pyramid that the girls made, and jumps, falling on Big Momma's stomach. Then Andrew says, "Big Momma." but his mouth doesn't move.
Continuity mistake: When Big Momma and Leah are teaching the children to dance, in one shot there is a closeup of Molly putting her head down and laughing. But a split second later they go to a long shot and she is now up straight listening to her iPod, with no time to move.
Continuity mistake: When Mrs. Fuller is telling Big Momma that the girls walking by in the spa are Victoria's Secret models, the gold watch on Big Momma's left hand is missing and you can see the seam of the costume on Big Momma's wrist. And in the next shot, the watch is back again.
Revealing mistake: At the end when Big Momma is dancing with Carrie's dancing group, when Big Momma does her flip, you can see a tape marker on the floor for where Big Momma stops. It is gone in subsequent shots.
Factual error: You can tell that the "Brillo pad" Andrew eats is not real as Andrew would have been VERY ill due to the cleansing chemicals on the pad and the fact that the metal would have cut his mouth considerably. There was no blood, no foam coming out of his mouth (the box says Oxy action implying foam), and he keeps eating despite that the taste would have been horrible.
Continuity mistake: During the bingo scene when Big Momma is about to fight the drunk elderly women, the picked numbers on the bingo board change from shot to shot dramatically.
Factual error: I used to cheer at major competitions like at the end of the movie. These competitons have VERY strict rules concerning music and acceptable moves. Carrie's cheer team would not have been allowed to compete with the song they use and some of the moves they do. They would have been considered vulgar/ inappropriate for their age group and the team would have been immediately disqualified.
Revealing mistake: When Stewart is working on his laptop at the satellite dishes, it is very obvious that he cannot type. He is tapping the keyboard repeatedly with several fingers, without moving his hands.
Continuity mistake: When Big Momma is zipping up her dress at the beginning of the movie, the coat hanger she is using changes its shape between shots.
Continuity mistake: When Big Momma is making breakfast the morning she is supposed to be fired, she is wearing a necklace. After the family comes downstairs, the necklace is gone.
Continuity mistake: When Malcolm/Big Momma goes to the beach, he is wearing a prosthetic bodysuit as we can see in shots of Big Momma in a bathing suit. He puts on a sun dress to cover up. Not long afterward, he chases Bishop down a pier and his mask comes off. We can see a heavier cloth bodysuit underneath the dress on his right shoulder, but Malcolm had no opportunity to change bodysuits.