Factual error: This episode was mentioned by Laura at the beginning as taking place in December 1889. Rose was born in December 1886, so she should be 3 years old now, but she is shown through the episode appearing only to be roughly 6 to 12 months old and still in a crib.
Character mistake: Almanzo says he hasn't seen his brother Royal in 10 years, but in fact he saw him not long ago as he looked after his 2 sons who were terrors, and at that time Royal didn't even have a daughter.
Laura: I wanted to clean the blackboards extra good today, to make up for being late.
Mary Ingalls Kendall: And talking in class?
Laura: I was not talking.
Mary Ingalls Kendall: You were, too.
Laura: Was not! Nellie was talking and I was answering.