I've just gleaned your post on the SALANOA board, and I just want to help you to help your son because as with all children their one question leads into many (and your child's curiosity is no different from the many curious-seekers growing up today).
The surname SALANOA is an old and revered name in the Samoan community.
The thread/post to which you'd responded to is the SALANOA of American Samoa[AS] and from your earlier post your SALANOA aiga/Family is of Savai'i, what used to be Western Samoa[WS].
Suggest going back to the SALANOA board and re-posting your message to reflect that your SALANOA is of the WS area that way you're likely to get appropriate responses.
Did your tina/mother tell you anything about the SALANOA name? Did she tell you the SALANOA name is a matai title in the aiga? Or is the SALANOA an original name of the aiga? Are you from the _big_ SALANOA Clan? Or are you an off-shoot of the original SALANOA name? Are you one of the many branches of the SALANOA name?
Remember your son's one question can lead into many questions asfaras genealogy is concerned.
I have a few... why can't I find the name SAUPATI? Is SAUPATI a fairly new surname? An off-shoot of a much bigger name? Is SAUPATI your grandfather's original surname? Are your grandparents still living?
Remember: Genealogy is dealing with the past/passed-away/dead.
The data/records genealogists are looking at is not to be taken as gospel truth/evidence. Those records have to be checked against other records (if you find them) then in the long run it is your own good sense to decide if written data or oral history--which one?--is right for what you're seeking.
Let me end this real quick. Polynesian genealogy is more than just written data, it is more oral history and you're not going to find oral history written down (when dealing with Polynesian oral history). Maybe a few but the few out there is so small they're called "rare" by today's standards.
"...never met any of Salanoa or Saupati family from my mother side, sad a ea..."
In my experience, you're safer not knowing anything at all about the aiga/Family especially "In the Beginning..."