Hi Sandstone
A little further information, which also serves to confirm we have the correct Christina.

A travel record (@ ancestry.com) for passengers returning from UK to New Zealand, has the following info >
"Rangitoto" (NZ Shipping Line) - bound for Wellington, New Zealand - departed UK 12 April
1957,
Ticket # 1942 :
EAGLESON - David - retired - (dob. = 25-08-1873)
EAGLESON - Mrs Christina (dob. = 2-12-1889) ... both NZ Citizens ( travelling on NZ passports)
... their last address given was : c/- Mrs M G ARTHUR, 58 Braewick Road, Lerwick ~ Lu
added : Another less detailed list (ex NZ Immigration - found at FamilySearch site), confirms Mrs Christina EAGLESON's birthplace was Scotland.