Lesya Line Lebedev

Backstory

I was a student of Koldovstoretz in Russia. When I was on the sixth year there was terrible accindent in the mountains behind my school. I was going with my school mate because we needed herbs for our Herbology lessons. But something went wrong and started avalanche.
I waked up in my present form. I am not the ghost. I am not the human. You can touch me and feel skin and bones, but I'm not aging. I'm still this sixteen years old girl.
That was one century ago.
So who am I?