I am not sure but perhaps Ahenita is the transliteration of the English Anita?
You have been given information about the children.
http://www.maorilandonline.govt.nz/gis/owner/interestSearch.htmThe website above is a listing of Maori blocks and it has the owners of the land. Generally to have an interest you need to be able to whakapapa back to a person that holds an interest in land. People who hold an interest in land hold it in the area that their family comes from, their turangawaewae or place to stand. When that person dies the family 'succeeds' to the interest of that person.
On the website I can see an entry for Benjamin Arkwright Thorpe. I have looked at the entry and the area that is given appears to be up the Mangapoike Valley. This valley is very close to Frasertown. (I come from Wairoa) I am not sure if there is/are marae up this valley. I know that there are several close to Frasertown.
https://www.maorimaps.com/marae/te-mira-whet%C5%AB-m%C4%81ramamill-p%C4%81It may be that Ahenita's land interests were around here. What I would do, apart from obtaining a photocopy of the marriage certificate of Ahenita and Stephen Thorpe is to do a tree for all of the children of Stephen and Ahenita. This will show how the current day people can whakapapa back to Ahenita. Or perhaps just do the line for the youngster you are helping.
The marriage certificate may show the names of the parents of Ahenita.
Once you have got the names of the children and grandchildren I would look them up on the site above. I have looked at several of the entries for the Thorpe family on this website.
From my very cursory look at some of the Thorpe entries it seems that the family has been diligent in bringing the interest of present day people forward on to the Maori land record. (When you look at some records around the country there are cases where there has been no action on the land for many many years. The land is still held in the names/s of people who may have died in the 1890s or 1900s.)
I believe that if you have the name and block number of the person that your friends whanau whakapapas to you could contact the staff at Maori Landonline and ask how, or if, the records can be searched back to find out the original owner of the blocks. It may give the family first name for Ahenita and others of her siblings.
It looks like one of Ahenita's daughter's married a Morgan. Sometimes this is transliterated as Mokena.
I am not sure if your friend has any contacts in Wairoa but someone may be happy to do some introductions or really 'reintroduction' as it is family making contact with family. I know that at some marae they have days or weekends when they do have genealogy workdays and help each other.
With the greatest respect to a previous poster but I think that the canoe for some/all? of the Frasertown marae may be Takitimu.
Stephen Thorpe was a valuer and later a farmer farming at Turiroa out of Wairoa on the road to Napier.