"I read somewhere that thin brows are seen as 'common', and royalty mustn't overpluck."
You could be on to something there, esp. considering the eyebrows of Wallis Simpson
, p'raps that was the real reason they couldn't stand her. Also reckon Princess Margaret fond of a shaped eyebrow during her more wayward phase, over-plucked eyebrows must bring back dreadful memories for them...
I'd love to have my Brooke Shields eyebrows back, I was always careful not to overpluck during the 80s, then about 1994 I suddenly wanted to have arched brows like Lisa Stansfield.