|First Appearance||"The Rye"|
|Last Appearance||"The Finale"|
|Portrayed By||Frances Bay|
In "The Rye," George tries to replace the marble rye his parents stole back from the Rosses. He asked Jerry to purchase one from Schnitzer's, but as Jerry gets there, Mabel buys the final marble rye. After refusing to sell Jerry the rye, Jerry steals it from her and insults her.
In "The Cadillac," Mabel appears as a resident of Del Boca Vista and has to cast the deciding vote in Morty Seinfeld's impeachment trial. Initially, she does not recognize Jerry, but when she does, she votes in favor of impeachment.
In "The Finale, Part 2," Mabel appears for the final time. As she was taking the stand, Jackie Chiles objected because she wasn't at the scene of the crime. District Attorney Hoyt states that they plan to use a series of character witnesses and Judge Arthur Vandelay overrules the objection so that he can hear what she has to say. She testifies against Jerry. She brings up the fact to District Attorney Hoyt that he stole the marble rye from her. While the jury was deciding on the verdict, Mabel was seen lingering in the halls of the courthouse alongside Justin Pitt and some other people.