Perhaps. Sounds logical. Shaman had a big hand in stabilizing Narya into a human-looking baby. Later, he and James may have determined that "a blonde-haired" Narya would fit in better, given that her eyes are unusual. However, The Old Gods could have chosen someone else, if ethnicity were their main concern, couldn't they?
I'm just saying that Narya has been presented as a transmorph/shape-changing demi-goddess. Easton is a part of who she is, no question about it, and his heridity would show up in her. As she gets older and more experienced or circumstances dictate, Narya may decide to change her appearance to something else. I believe she's capable of doing that,
if she chooses to.