No, I knew the Australian Open was held in December in 1983 and 1984.
I remember skiing in Vermont in December 1984 while the Australian Open was going on. By then, I had been going to the US Open since 1981. Edberg may won in 1984, just a guess
And I know who Margaret Court is, of course. One doesn't have to know much about tennis - she did very well at the Australian Open for the reasons you stated