I did talk to him about changing the spelling to a more phonetic one, but his opinion on that is its not really honoring his grandma if we do that. I've been thinking of trying to add that dash thing above either the a or i.. Sorry I'm terrible and have no idea what they are called or if that would even be appropriate. I'm talking about Náir or Naír... Someone with any knowledge on that chime in please!
Naïr? I think that one works, since the ¨ is supposed to sepparate vowel pronunciaton (don't quote me on that - my French is very rustt!), sort of like Anaïs.
Of the other two, it would have to be Naír, though it's not really a correct place to put the accent, but who cares - it would work to clarify that the vowels should me pronounced separately and which one has the emphasis.