Well, I didn't really have anyone specific in mind when I drew her. I was also kind of sorry I drew it without reading the descriptions one more time, cuz there are quite a few mistakes here, but this was drawn during a school lesson. But yeah, since Iza was the one who had the most impression on me as a character, it would make sense that there's a sort of Iza "Air" to her... Perhaps this is what she was like when she was younger..? XD
Actually I was looking up "Neanderthal" and this came up, and my very first instinct, after seeing tonnes of pictures that didn't quite "do it" for me, was "Yeahh, now THAT'S how I reckon the Clan people would have looked!" and then when I read the description, I realized you were actually doing this based of the books!
Hahah yeah, a young Iza, I would call her Nice work!