I placed the enquiry on the message board for John Johnston
What I have found is He married Anne Ambrozine Henderson in Orange NSW in 1878
Her father was William Henderson.
Anne was born 4 Dec 1860 Campbletown NSW Died 26 Feb 1947 in Adelaide Buried at Cheltenham Cemetery
Had a daughter Beatrice Mary Johnston born 1880 died 1964
Not sure when she married Charles Cole
Had 2 children to Charles
Charles Cole Born 1895 Died 1969
Ellen Matilda Cole Born 1897 Died ?
Then I have found Mary Ann Williams Johnston (Father Edwin Williams) this is on the birth notice
Married Gotlieb Neils Jensen Born 1857 died 1942
Married on 18 Nov 1905