Hello Catherine
What a nice surprise.
I did some research back in 2010/11.
A copy of Register of Marriage for Robert & Bessie has them marrying on the "26th March 1861 In the Dwelling House of Charles McDonald Parnell" Auckland. It shows both aged 25 and Robert is a Cabinet Maker. They were married in the presence of Charles Scott McDonald (occ: Gardener) and Margaret McDonald. [source: Registration No. 1861/1675 BDM govt nz].
I also have a possible ship arrival for Bessie Adelaide ELLIOTT on the Frenchman
Entered Inwards. March 22— Frenchman, ship, 1156 tons, from London
Sarah & BESSY ELLIOTT
Source: Daily Southern Cross, 23 March 1860, Page 2
Shipping Intelligence. PORT OF AUCKLAND. Papers Past
Regards Tracey