I recently got season 2 (yea, I'm way behind) and this episode was a really enjoyable one! First, Buffy practically spends the entire episode not in her trademark pigtails and that was refreshing, but the story itself was superb. Buffy makes friends with a bunch of working class/poor kids but feels the need to hide the fact from Mr French, who is insisting on trying to instruct Buffy as a proper mannered young girl. Uncle Bill agrees to help her with the secret and both are mistaken by the others to be of the lower working class themselves. When the secret is revealed, Uncle Bill does his best to patch things up because Buffy relating to other kids, esp those not in her neighborhood or social status is important.

Jackie Coogan plays the father of one of these kids and here he is not doing his usual gruff sitcom type that he was always cast as. It really works well.
Even Mr French realizes he himself has been too "upper crust" in his instruction with Buffy.

Yes Jude, of all the "Family Affair" episodes, there are only a select few that really stand out to me and this is one of them. There was something even a little creepy about the beginning, where Mr. French leaves Buffy all alone for that lesson of hers.

I think "Fat, Fat" is my favorite episode because the story was so unusual, not your usual sitcom fodder. If you like this one, you will probably like the upcoming Season 3 episodes: "The Latch Key Kid", "Albertine", "The Substitute Teacher"; and also Season 4's "The Language of Love". They are all standouts IMO.

I will be getting Season 3 sooner or later...maybe for birthday or Christmas.
Looking forward to seeing the kids get older and having more episodes spotlighting more "growing up".