In the Presbyterian section of Gore Hill Cemetery on Sydney’s North Shore lies a rectangular headstone with a plaque that bears this epitaph:            MAIDIE WIFE OF WILLIAM COWAN 24th MARCH 1919 The plot in which the headstone is set is square, curbed and filled with pebbles. A small tree stands nearby; sometimes, when there is a breeze, a light scattering of leaves from the tree falls across the words inscribed on the tablet. Here lies Marie Cowan, whose arrangement of “Waltzing Matilda” is the tune we sing today. Of her nature and personality I have no special knowledge. All that…