Continuity mistake: They mention that the goose has hatched out 7 goslings. They say there were 8 eggs and one didn't hatch. The one egg is given to Templeton, and it is later smashed open. Later that night as they're going to sleep, the mother goose has 7 goslings under her, but then then it shows Jeffrey (one of the goslings) sleeping with Wilbur. Seems they had an extra gosling with the mother.
Continuity mistake: When Fern is outside talking her father out of killing Wilber, her little brother is inside coming to eat breakfast. His plate is empty at first, then has pancakes on his plate and the next shot he is putting the pankcakes on his plate.