Hello Mavis,

You have probably seen the entry on the IGI for CATHNE JANE CRETNEY bapt 3 Dec.1846 at Saint Barnabas, Douglas, daur of RICHD CRETNEY & ELIZTH.

Death certs are notoriously inaccurate (because written by someone else). Where and when did she marry William Byford? Are her parents given on her marriage cert? Who were the witnesses?
Was the NZ family in touch with her siblings? When did she arrive in NZ, and who did she travel with? What was written about her on the passenger list?

Sue