A lot of relatives who have appeared on Celebrity Family Feud likely only have that one game show appearance to their name.
Actually, now that I think about it, there's probably a sizable list of celebrities who appeared on a Combs-era Family Feud celebrity week (and probably some of the Dawson-era specials, too) who didn't make an appearance as a celebrity on any other game show.
I'm guessing that Kim Hood, from WTHR in Indianapolis, only did Match Game/Hollywood Squares Hour.