....... Mothers name unknown said to be from Royal Stuart Clan. His father John a highland baird.. When John was little his mothers brothers came and took her home. Now he and his father came to NZ. ......
Noting the word above 'baird'.
Is this meaning Baird, the surname?
or
A Highland laird?
Laird”, a Scottish term, is a title reserved for those who own larger estates or pieces of land in Scotland....'
So a laird had a relationship with a woman of the Royal Stuart* Clan?
Have you looked at the any Clan history?
https://en.wikipedia.org/wiki/Clan_MaclachlanI would have thought that a Laird going to NZ in such circumstances would have figured in some historical accounts. There is a branch of the clan here in NZ.
Scotlands People has all sorts of records of even informal marriages, not much escaped the powers that be.
* have you mentioned the clan with the spelling Stuart as part of the story......the more common spelling of the clan name is Stewart but there is a branch that kept the French spelling - Stuart.
These are the Stuarts of Bute
' Clan Stuart of Bute
'The chiefs of the Clan Stuart of Bute are descended from Sir John Stewart, illegitimate son of Robert Stewart who reigned as Robert II of Scotland by Moira Leitch (according to tradition)' Wiki
Also from Wiki
https://en.wikipedia.org/wiki/Clan_Stuart_of_ButeThere may be some genealogical tables for this clan that you could find.
On the basis that the 'Royal' is part of the tale
https://en.wikipedia.org/wiki/House_of_Stuartthe Royal house of Stewart....
https://en.wikipedia.org/wiki/House_of_Stuart#House_of_Stewart