Muffy Gets Mature

Muffy Gets Mature is the second half of the 10th episode of Season 5. It first aired on November 6, 2000 with Arthur's Family Feud.

Summary
Muffy hangs out with Francine's sister, Catherine, because Francine is not mature enough. Catherine's friends don't receive Muffy well and ridicule her because she uses "Mature Miss" as her guide for acting mature.