Hi, I am not a relation but my second cousin's husband probably is and I am looking on this site for his rels. I have an Agnes Jane Wyatt, who was born in NZ in 1880. Her parents were William Wyatt and Annie Woods. On Agnes' marriage certificate, she got married at the home of her father, William Wyatt, in Hamilton West, NZ. She married John James Richards in 06 Aug 1900. I am pretty certain that she is the one of the extra sisters that you are looking for. Her age fits in with the age of the youngest daughter (aged 23) when Anne Wyatt died in 1903. You can find the reference to her birth on the NZ BDMs website:
http://bdmhistoricalrecords.identityservices.govt.nz along with her parents names. John and Agnes had 4 daughters: Mildred, Florence, Gertrude and Rona. Paige (2nd cousin's husband) in descended from Gertrude and lives in Wellington. Let me know what you think and if you need any extra info on this one.