Gretchen Grossbard is a friend to Stan's pretend father Grandpa Smith who becomes a lover to Steve and Snot in "Con Heir", claiming "monogamy is for girls in their 60's." It is later revealed she had not consummated the relationship.

She sings a tribute to her sister, Irene in "Phantom of the Telethon".

Gretchen is voiced by Sherry Weston in "Con Heir" and by Laura McCreary in "Phantom of the Telethon".