Is this the daughter ?

New Zealand, Marriage Index
Name: Emily M Duke
Marriage Year: 1874
Spouse: Robert Johnston
Folio Number: 2492

New Zealand, Archives New Zealand, Passenger Lists
Name: Emily Duke
Event Type: Immigration (Assisted)
Event Date: 25 Oct 1872
Event Place: Otago, New Zealand
Gender: Female
Marital Status: Single
Nationality: Surrey (This is a county in England)
Occupation: Servant
Departure Date: 1872
Arrival Port: Otago
Arrival Place: Otago
Digital Folder Number: 004411653 , Image Number: 00006

Ship: May Queen, saied 25 Jul 1872 arrived 25 Oct 1772

Also listed;

Parents: George Duke 47 Priscilla 44 (wife)
Children:
Priscilla 22 ; Sarah Ann 20; Emily 14; george 11; Agnes 9; William7; Martha 3.

From Surrey, England. Occupation of George, Bricklayer.

You can get a copy of the ships records from FamilySearch.org (free site). just enter Emily's
name, marriage place New Zealand 1870 -1775. There is a R Johnson on page 3. age 17

There seems to have been some names transferred about for some reason you might have to go from page to page

Robert Johnson
New Zealand, Archives New Zealand, Passenger Lists
Name: Robert Johnson
Event Type: Immigration
Event Date: 25 Oct 1872
Event Place: Otago, New Zealand
Gender: Male
Marital Status: Single
Nationality: Shetland
Occupation: laborer
Departure Date: 1872
Arrival Port: Otago
Arrival Place: Otago
Digital Folder Number: 004411653 , Image Number: 00011
.....................................................................................

1861 Census
Name: Emily Duke
Age: 7
Estimated Birth Year: 1854
Relation: Daughter (Child)
Father's name: George Duke
Mother's name: Priscilla Duke
Gender: Female
Where born: Chiddingfold, Surrey, England
Civil Parish: Farnham
Ecclesiastical parish: Hale
County/Island: Surrey
Country: England
Street address: Hungry Hill, Farnham, Surrey

George Duke 39 Bricklayer Chiddingfold, Surrey, England
Priscilla Duke 34 Dressmaker Farnham, Surrey, England
Priscilla Duke 10 Scholar Chiddingfold, Surrey, England
Sarah Duke 9 Scholar Chiddingfold, Surrey, England
Emily Duke 7 Scholar Chiddingfold, Surrey, England
Mary Duke 6 Scholar Chiddingfold, Surrey, England
Henrietta Duke 2 Farnham, Surrey, England
George Duke 4 Farnham, Surrey, England

London Metropolitan Archives, Saint Mary, Whitechapel, Register of marriages
Name: George Duke
Spouse: Priscilla Prince
Record Type: Marriage
Event Date: 2 Jul 1849
Parish: St Mary, Whitechapel
Borough: Tower Hamlets
Father Name: Thomas Duke
Spouse Father: Daniel Prince
Register Type: Parish Register

Yes, This couple, Robert Johnson (later Johnston) and Emily Duke, are my husband's g.grandparents. That's a lot of data there! Thank you. He was a tailor.