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.
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.
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.