|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 marble rye, Jerry steals it from her and insults her.
In "The Cadillac," Mabel appears as a resident of The Pines of Mar Gables Phase II and has to cast the deciding vote in Morty Seinfeld's impeachment trial when Jack Klompus accused him of embezzlement. There was a reference when speaking with Morty and Helen Seinfeld that she was up in New York visiting a relative of hers at the time when the marble rye she bought was stolen from here. Initially, she does not recognize Jerry. When she does recognize Jerry when it comes time for the deciding vote, she finally remembers Jerry and votes in favor of impeachment while telling Morty that his son stole her marble rye.
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 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, Marla Penny, Joe Bookman, Marcelino, and some other people.