There were wimmin flogging RPT Herons with Southern Airlines out of Essendon in the early 1950s - before Deb Lawrie was born.
Thats entirely the point! Why weren't they then allowed to progress their flying up to airlines such as ANA, TAA and Qantas? Deb, through legislation bought in by the government of the day (hint: not Gough and his socially progressive hippies) was able to demonstrate that being a woman was not a barrier to doing the job professionally. Yes there were woman flying RPT but only in the "second tier" of RPT services.
I have had the pleasure of flying with Deb and I could see why Reg was never going to win.