You were very, very close and went off on a tangent
The answer is Harry Mc Evoy's only daughter, Tien (short for Cettien) who when still 15 set the Oz record at 67.9 over the mile in 1935. Tien was born on Oct 9, 1919 and died in Penrith hospital aged only 64 0n May 12,1984. Google Tien McEvoy and you will find an article re a very handsome gift to her from St George MBC in 1935.
As for Sunray 11 it did get the record (83 I think) in 45 or 46, ie Tien's rcord stood for 10 years. AND this boat was Cettien re-named and re-engined with a Merlin. It was a very dangerous boat and kept revolving eround the prop shaft as it could not handle the power/torque. Cettien origially had a 450 hp motor. It was retired before someone got seriously hurt.