|Family|| Cousins: George Costanza & Unnamed Cousin
Uncle: Frank Costanza
Aunt: Estelle Costanza
|First Appearance||"The Contest"|
|Last Appearance||"The Contest"|
|Portrayed By||Rachel Sweet|
Not much is known about her, only that she is a cousin of George Costanza, and niece of Estelle and Frank Costanza. She visited her aunt Estelle in the hospital after falling after she caught George with a Glamour magazine. Shelly knows about George's writing job at NBC, as she had asked him about it during the visit, but he failed to answer due to the sponge bath of a female patient nearby.