Continuity mistake: When Jo returns home from New York after she learns Beth is sick, she enters the room and Marmee stands up to hug her. When they hug, Marmee's arms are between them. In the next shot, they're around Jo then they switch back to being between them.
Continuity mistake: When Laurie sees Amy painting in Europe, in his closeup he takes the cigarette out of his mouth and throws it on the ground. But in the next shot, with Amy in the foreground, as Laurie is walking towards her in the background, notice how he, once again, removes the cigarette from his mouth and throws it on the ground. (01:21:45)
Continuity mistake: In Beth's death scene check the arrangement of pillows under her head. It changes several times before and after she dies. (01:32:45)
Continuity mistake: When Amy is struck by her teacher and Marmee writes Mr. Davis a letter chastising him, when Jo says inappropriate things about Mr. Davis, Marmee assigns Amy's education to Jo. When the camera shows Jo's reaction, behind her you can see Amy sighing and slumping in disappointment, and then the camera cuts to show Amy doing the same exact thing again. (00:24:20)
Audio problem: When Laurie gets a letter from Jo in which she tells him about Beth's death, you hear her reading it in a voice-over. She says "come home to us", while her handwriting says "come home to me". A small, but in this special case significant difference. (01:36:50)
Continuity mistake: At the second Christmas party Jo talks to Laurie while she is sitting on the stairs, looking through the bars. In all close-ups her head is much higher, half hidden by the railing and the Christmas decoration. (00:59:45)
Other mistake: When Beth visits the Hummel's house, the Hummel baby is supposedly crying because he is sick. In reality, the Hummel baby is crying because the Hummel mother accidentally bends back the baby's foot, when she hands the potato that Beth gives her, to one of the Hummel daughters.
Continuity mistake: When Friedrich talks to Jo in the hallway about her novel, you hear the footsteps of a man coming, and you see him stop right behind Friedrich. The camera cuts briefly to Jo, then back to Friedrich, and the man is gone. Given the acoustics of the hallway he had no chance to walk off secretly. (01:28:20)
Continuity mistake: When Laurie and the girls are playing in the snow, Marmee comes out of the house with Meg, carrying firewood. The way the logs are arranged in her arms changes between shots. (00:19:25)
Continuity mistake: At the end of the movie when Jo runs after Friedrich to stop him from catching his train, she runs along a path with high trees on both sides. After she catches up with him you see the path where she came, and the trees on one side are gone. (01:49:30)
Continuity mistake: When Laurie is named Roderigo and joins in on the girls' fun, one of the girls places the hat on his head and they all bow, but in the next shot, he puts the hat on himself, and Amy turns it and bows yet again.
Continuity mistake: When the March family sings carols on Christmas Eve the piano is tuned quite well. The next morning, when Beth plays again, it's totally out of tune, which shouldn't happen over night. (00:06:30)
Continuity mistake: When Jo and Laurie pull Amy out of the ice hole there are a number of continuity problems. For example, Jo pulls at Amy's right arm, but in the next shot the arm is in the water again. Plus, in one shot Jo is visibly laughing. (00:35:15)
Continuity mistake: When Laurie pulls the sleigh with Jo and Beth we see a bit of Amy who jumps on too. In the next shot we see Amy running after the sleigh and jumping on again. (00:19:00)
Revealing mistake: When Amy comes back home from Europe she gives her parents one of her paintings as a gift. It is wrapped in lace, but in the close-up of the unwrapping, when the ribbon is removed, you see that the lace is only on top, covering the painting, not wrapped around as it's supposed to be. (01:43:55)
Continuity mistake: After Friedrich criticizes her writing Jo storms into her room. When we see her inside the room she is coming from the right, but when Friedrich knocks a moment later to apologize she goes to the left to open the door. (01:17:50)
Continuity mistake: When the father of the March family comes home at Christmas, he's shown standing right in the frame of the camera, then just walking in when Meg notices him, to just standing inside the frame, to walking all the way in.
Revealing mistake: When John is brought to his wife who had just delivered twins, you can tell from the babies' faces that they are several days old. (01:41:50)
Character mistake: Jo says Laurie is a "captive like Smee in 'Nicholas Nickleby.'" There is no such character in "Nicholas Nickleby." The character Jo is referring to is named Smike.
Chosen answer: From what I heard of the text, it's The Bible.