Jackie ..... I am distantly related to Jane Wyvill. She married James Kosciusko McDonald (b Liverpool England,circa Sept 1840) in Brisbane 29 July 1865. They had three children that I know of, ..... Sarah Jane Shepherd (nee McDonald) (1868-1960), James Kosciusko McDonald (1870 - ?) and William Wilcock Wyvill (1872 - ?). Unfortunately, James Kosciusko McDonald snr died 24 August 1871 and never got to see his third child. Jane may have remarried but I haven't been able to trace her. Their daughter Sarah Jane married Thomas Shepherd in 1887 and went onto have 2 girls and 3 boys. I have some detail on these if you want it. James Kosciusko McDonald snr had a brother (Donald - my family line) and sister (Sarah Elizabeth) both of whom lived, married and had children in Sydney.
If you uncover anything on the Australian Wyvill's I would appreciate any information you find.