When Big Momma is confronted by the lady wanting to fight her at the bingo game, you can see Carrie turn to her and mouth the word, "Big Momma" though you can't hear her. Then there is a close up on her saying, "Big Momma, do you even know this lady?"
When Big Momma lays the breakfast table after cleaning the house to avoid getting fired, she is wearing a pearl necklace. In the next shot, it is missing. When she returns from the spa with Mrs. Fuller it is there again.
Throughout the movie, Malcolm uses 2 different methods to transform his body into Big Momma. One is through the use of a body suit (made of a stuffed cloth material, which is used when Big Momma is wearing a dress) and the other one is through the extensive use of prosthetic makeup (for when Big Momma is showing more skin, at the spa and at the beach). In the beach scene, Malcolm is clearly using the prosthetics when Big Momma is in a one piece bathing suit as much skin is exposed. Big Momma then puts on a big sun dress to cover up (while still wearing the bathing suit and prosthetics). Moments later, she starts chasing Bishop down the beach to the pier. After Bishop jumps off the pier and Malcolm (now with his mask off) looks over the pier, you can see under the big sun dress on his right shoulder that he is wearing the fat suit, not the prosthetics. There was no opportunity for him to have switched from one to the other.
In the scene where big momma shows how to shake the butt inside the house, you see a close up-shot of one of the girls laughing and then hiding her face (behind her iPod?), and in the next scene she can be seen in the background with her hands down on her lap, nowhere near her face.
When Big Momma is in front of the Hasidic synagogue, most of the men are all wearing large prayer shawls. In fact, the large shawl is used only during the daytime. The men would only have been wearing small ones.
The Fuller's dog is referred to as Poncho, a male Chihuahua. Yet, when all Carrie's fellow cheerleaders show up to the house to practice their routine, Poncho stands on his hind legs - and it's clearly a female Chihuahua.
When Sherri, Malcolm's wife, is talking to her friend, showing her the large panties she found under her bed, the sides of the underwear change from back to front with no sign of Sherri making the change.
In the scene where Big Momma is pouring milk into a box of Lucky Charms for Carrie you see that after she pours in the milk, she places the milk bottle down upright, but in the next scene the milk bottle is on its side face down and crushed, yet again in the next scene it's upright and normal again.