There is an 1841 census record for an Elizabeth Stephenson with parents James and Ann. Birth year transcribed as 1836. James is an Ag.Lab.
Residing at Todhills, Auckland St Andrew, Auckland, Durham
Registration district Auckland
Archive reference HO107
Piece number 303
Book number 1
Folio number 6
Page number 6
I'll see if I can find a baptism for this Elizabeth.