Let's try this one again.
From season 4 of The Mary Tyler Moore Show:
Mary heads to New York with bestie Rhoda Morganstern (Valerie Harper) for the wedding of Rhoda's younger sister, Debbie (Louise "Liberty" Williams), who's only 21. Debbie falls into the category of forgotten siblings because she was never heard from again, and when Rhoda was spun off into her own series, she was given another sister, Brenda (Julie Kavner, currently on The Simpsons). Nancy Walker (McMillian & Wife) & Harold Gould play Ida & Martin Morganstern. Brett Somers (Match Game) also guest stars in "Rhoda's Sister Gets Married":
I think Debbie's parting gifts included a case of Bounty paper towels, which Nancy Walker was shilling for back in those days.