Hi pixie
Ah ha,  .... was rather hoping John RYAN was one who could read and write.   

     Drat. 
The thing is though, here you have a very young girl (Emma), who didn't have permission from a near relative (or anybody else) to marry  ... all alone (apparently), ....  in New Plymouth.
I don't know much about the wars (or soldiers) in the 'Naki area, in those very early years, but I do wonder if Emma might have arrived in NZ as a family member of a soldier perhaps ?
Someone must have known her, known her name and how to spell it ?  
~   Lu