Well, enough time has passed by now to tell if it was so obvious, only one person cared enough to respond, or it actually stumped the average fan. Either way, here ya go: it was Anjanette Comer.
To explain my incorrect answer, the unlucky Mrs. Petrie.
I thought it was Antoinette Bower, Frances Galesko in "Negative Reaction". She was Dick Van Dyke's wife, that he murdered. Van **** was Rob Petrie on "The Dick Van **** Show". That photo looks a lot like Bower in her youthful days.