The Hole-in-the-Wall Gang - S4-E21
Plot hole: When Stephanie and DJ start singing that dad song in their room, Michelle come in and starts singing. After she goes, DJ and Stephanie have a talk. After two minutes, Michelle comes in, dressed like they are. How could a 4-year-old girl change to teenage clothes and fix her hair in two minutes? Danny was in his room (because he found the baking soda), and Jesse and Joey were too busy with Jesse and Becky's room to help her change.
Suggested correction: However it could have been Kimmy as she was seen in the tanner house hold not that earlier in that episode and may have never left.