Thanks Hallmark and gaffy for your postings with links to further information which is helpful.
I have also found a Mary Ebbitt, 17 years and Elizth Ebbitt 18 years, both GI Servant from Dublin who sailed on the ship "Hereford" from London on 31 October 1877 and arrived in Lyttelton, NZ on 19 January 1878 (info from FamilySearch).
Not sure if any connection though!
WNW