Have you looked at newspapers for the time period you're interested in? PapersPast (http://paperspast.natlib.govt.nz/
Electoral rolls may be another source for you - women have had the right to vote in NZ since 1893.
Two rolls have been transcribed and published on CD (1881 and 1893) and 1896 is due to be released on CD shortly. The first two have sold out (you might like to look for second-hand copies), but are included on the latter disk when it comes out.
Keep an eye out at http://www.genealogy.org.nz/Sales_11.aspx?CategoryId=11
for the new disk - this is where you'll be able to purchase it when it is available. If I recall correctly, the plan is to release it at the Family History Fair in Hamilton, which is at the end of next week. http://nzfhf2010.dnserver.net.nz/
Other years can be found in the original paper form or on microfiche.
I would check the 1893 roll for you, but have just discovered it won't load onto my new computer (had a hard drive crash a few weeks ago, and still recovering everything I had on the old one!). It might take a while before I can resolve that. Meanwhile, can someone else do this for Sue?
My only other suggestion at this stage is to post a query to the New Zealand board. This one might be too specific for your needs, since you don't know how long she spent on the West Coast, and likely travelled elsewhere. I don't know how many people read each of the boards, but I'd guess more follow the NZ one than this one, so you'd reach a larger audience and perhaps someone who can help you. http://boards.ancestry.com/localities.oceania.newzealand.gen...
Hope this helps. :-)
Kaiwaka, Northland, New Zealandhttp://freepages.rootsweb.ancestry.com/~wendyh65/