Hi Jenn,
I'll try another of my scenarios

People (especially those who inherited under a Will

) were often quite practical when it came to expense connected with purchase of grave plots.
Perhaps (or perhaps not) James COURT who m Harriet J HEASMAN in 1905 in Wellington, NSW (Harriet assumed to be the widow of William R; she d 1918, Wellington as Harriett J COURT, parents Edward K & Rebecca) was the "friend" who was 'responsible' for William's passing in 1897.
Regardless ...
If James pre-deceased Harriet, perhaps she - before she passed away - left instructions that she was to be buried with William (especially if she owned that grave and there was room for her), and instructions (and provision) for the headstone.
There's a James COURT age 76 d Wellington in 1916 (he might already have owned a grave in Wellington or elsewhere where he would be buried)
On the other hand, perhaps James outlived Harriet and had the headstone erected as a memorial to them both.
I wonder whether any of them left Wills ...
JAP
PS: A James L COURT was buried at Spicers Ck Cemetery (between Wellington & Gulgong), 2 Aug 1916, age 78 (his death registered at Wellington). There's a photo of his headstone.