(Caution: May be the weirdest question you have ever gotten)
(PS: It's sorta relevant to my last question about eyes :D)
So, if Sophie ends up marrying one of the blue-eyed elves, (hopefully Fitz) and happen to have little children elves, wouldn't that mean that she could possibly create a whole new group of elves with brown eyes and animal genetics?
Ha--wow, you are thinking very deeply into elvin genetics. And honestly, the only answer I can give is, "I don't think the elves know."
I'd like to believe that the uniqueness of Sophie's genes can't really be passed down without special genetic manipulation, just because so much was done to make sure she turned out the way she did.
But genetics can surprise people. Look at what happened with Sophie's eye color. It was a happy accident. So I don't think there's any way to know how Sophie's children would turn out until she had children--if she has children. She's a bit too young to have decided whether or not she will.