Complex character Margo. All the negative stuff around her haughty, superior, snobbishness is obvious but her lack of emotional nous made her very vulnerable to ridicule which really cut her (she could also be extremely thoughtful and generous as a friend) an absolute genius character creation played to subtle perfection by Penelope Keith.
I remember looking after "Margo" and her husband in Quills Restaurant , Carlton Highland Hotel, Edinburgh back in the 1980s. Some Yanks were hounding her whilst she ate. I told them the Tattoo started in 20 minutes, they soon shifted (even though it didn't start for a couple of hours 😂).. I had the pleasure of looking after them all night, great memory for me, Mick.
I love Margot but I fear you're right - although a figure of fun in some ways she made that type of Englishwoman a more familiar figure than was previously the case.