Thanks
I only have to think about the look of their parents. You're right, the mother is a stag-like creature. But I think about the father's look for first. Something with bear paws, I guess. And the father of the half-sister (I still have no name for her) can be about 500 years old. So his daughter can be too. Actually, she's the elder sister even she looks younger then her half-brother.
Hehe, I just gave my fancy full scope
. I'm crazy.