Until after WWII, many / most females of marriageable age in NSW were unskilled for any formal occupation away from home/household duties, and so you will often find on NSW BDM marriage registrations, particularly from say 1920 to mid 1950s that the bride’s occupation is either a horizontal line or it is ‘domestic’ or ‘lady’ or if their usual address is not the family home, then they are a ‘governess’ or ‘nurse’ or ‘teacher’ .
When following up on these ‘occupations’ I can assure you that it is just as frequent to find ‘domestic’ or ‘lady’ to mean ‘she still lives at home and helps with the domestic chores of daily living without being given any wage as though an employee’ as to find it meant ‘ paid a wage as a domestic servant’ and the occupation/profession/rank of the father had no real impact or bearing. Father could be a leading politician, perhaps even a Prime Minister or the most senior Barrister or Stock Broker or street cleaner, or not even named on the m.c. or perhaps in a state institution never to return to the family – shell shock from WWI - but ‘lady’ (or any other word) was simply the word chosen by the Clergy (rather than by the bride) to record on the marriage register.
I am sure that a similar concept (the clergy determining the descriptor/noun) would apply far and wide across Australia and likely throughout the then British Empire in that final flourish of Empire.
I should also note that in NSW “Esq” was frequently used as an alternative to ‘Mr.’ when addressing an envelope so Fred Bloggs Esq and Mr F Bloggs were one and the same in 20th Century to about 1980 … notice that Fred can be Esq but Mr would not be Mr Fred Bloggs … So basically, if you wanted to show you knew Fred then you wrote Fred Bloggs Esq, but if you did not know him, you wrote Mr F Bloggs …. And of course, Fred’s wife, regardless of her own given name, was Mrs F Bloggs … Social Conventions that have long gone now.,… perhaps even the NSW ones varied from district to district or from rural to urban and of course, across time.
JM