I think Carolyn is going to send you the full story.
Briefly, They married in NZ, had a son (Richard) in NZ then settled in Fiji where John had several plantations (and a hotel I think). Two more children were born there. In 1871 John was attacked and killed, along with another planter called McIntosh, by natives. Jemima took the 3 children to Sydney in 1873.