There is a headstone at Patea according to Cemetery Fiche, but no dates, only "To the memory of Jane and William Gadsby"
BDM site has a number of children with parents William and Jane from 1880 to 1887. Looks like Jane died in 1891 aged 38. No marriage in NZ for a William to Jane, but there is a Marriage in 1893 for a William to an Elsie SOUTER, possibly a second wife.
A few marriage notices of children on Paperspast. Also about the death of Jane in late December 1891. They had seven children four sons and three daughters
Looks like Jane is buried at Patea as well.
Ian C