Not one of the girls appeared in every single episode. They were each absent for at least one episode. Of course Mrs. Garrett left the show after seven seasons and Jo doesn't arrive until season two, so that instantly takes them out of the running. Natalie misses an episode in season seven, "The Lady Who Came to Dinner". Tootie misses an episode in season nine, "Something in Common." Blair infamously missed "The First Time", in which Natalie loses her virginity.

So that's it. 201 episodes (209 with syndication) and not one of the girls appears in every episode. The only one I was aware of was Blair. Natalie and Tootie each missing an episode was news to me.

Yes I knew that. That was a real travesty that no one appeared in every episode. We obviously know why Blair was absent from that episode because of her beliefs, but why were Natalie and Tootie absent from the episode that they each didn't appear in. I haven't ever found an explanation on that.

I think Mindy may have been absent because of the movie she was in The Boy Who Could Fly. Possibly