"All in the Family" was pretty bad at this late point in the series, and this show is more good evidence of it. Archie's pal Barney is alone again after his wife left with the "furnace man," and Archie and Edith set him up with a friend of Edith's named Martha who is on the heavy side (which of course leads to some typical fat jokes).
The thing is, Martha is wealthy as she is a widower who was left three supermarkets by her husband. She sold them and invested the money, including in lots of diamonds. However, Barney never really gives any indication that he is gold-digging - he actually tries to run from the idea, even after Archie told him about the supermarkets. Even with that, Archie told Barney she "used to" own them, without explaining in more detail, so Barney really has no idea of Martha's current wealth. Barney even states quite earnestly that he "ain't for sale." He then starts seeing Martha, but again, there's never any evidence that he is gold-digging, despite Archie and Edith's believing that would be Barney's main motivation for taking Martha out.
Edith looks like a pretty bad person in this episode. First, she answers (with her facial expression) Archie's question on whether Martha is a "dog" or not (she's saying "yes"). And later, Edith "warns" Martha about Barney's gold-digging, despite, again, absolutely zero evidence of such.
Outside of a few jokes at the expense of Martha's weight, if one considers them funny, there's virtually no laughs at all in this lame episode.