First, about that quote, I dont recall it. I remember Talon saying something like "it awfully looks like Malon's mother". I think it depends of the version you're playing.

Then, I imagine Malon being some kind of albino Gerudo. But seriously, you have good points. But it is still possible for a Gerudo to disagree with her culture and chose to live as a Hylian, just like Nabooru refused to obey her King.

You are right when you say that orange hair is not enough to prove that she is half gerudo, as other characters have been seen with orange hair. But I think we can consider Talon's quote as true. But the fact that the quote have changed might prove that the developpers changed their mind about Malon's mother.

Its been discussed a lot, and I remember a topic about biology of different races, and I think it covered a little bit Malon. Good topic anyway.