Hi Maggie its usual that the surname would be that of the mothers maiden name. Sorry this is no help to you as mother is unknown. Also there seem to be two merges in this profile to do. Isabella Pakewa and Isabella (Pakewa) Nukaiahu — will most likely be the same people.
ALSO
the same for Paeroke Rawiri and Paeroke (Nukuaiahu) Jenkins UNLESS one Paeroke died and then the new Paeroke was named after him but from the dates it appears unlikely.