Welcome To Olesonville - S9-E3
Continuity mistake: Mrs Olsen cleans up the old Hansen house to sell, however it was made the blind school years back and burned down, killing Mary's baby and Alice Garvey.
Little House on the Prairie (1974)
Episode list - season 4
More mistakes in Little House on the Prairie
Laura: I hate that Nellie Oleson.
Caroline: Laura! Don't say "hate" - don't even think "hate"! I'm sure Nellie has her good qualities somewhere.
Charles: Your ma's right, half-pint. Now on the way home, we'll try and think of some.
Trivia: Star Michael Landon was born 100 years after the real Charles Ingalls. Ingalls born 1836 and Landon born 1936. Lindsay/Sidney Greenbush (who played Carrie) was born 100 years after the real Carrie. Carrie in 1870 and the Greenbush twins in 1970.