In any case, I doubt that RJ wanted to have two Queen Ethenielles of Kandor from different Houses, which still seem to have lived relatively close together. It seems like a mistake (at least if Ethenielle didn't change her name for some reason, e.g. marriage, as Lord Haart suggested).

Nothing in SaSG hints at Rand's growing influence in the world, thus one should probably place the writing of the text at the time between EotW till TDR, or maybe a few years before EotW (obviously the infos in the text aren't common knowledge in nowadays Randland, therefore it can't be that old). I tend to think that Ethenielle Kirukon Materasu is the correct name, since two sources mention it, and it alludes at Kirukan.

But you are right, only the notes can tell us the correct name (it might appear in the main series yet).