The Orphan: Ester's story?

I just saw Orphan yesterday and i loved it, i liked how she was really a grown woman and how she kills the husband. How exactly did Esther get sent to the Saarne Institute? I know she is insane and dangerous, but what's her story? It doesn't explain her background in the movie. I heard from other ppl that she killed her ually abusive father and was a prostitute for pedophiles, is this true ? Also, 2 things i didn't really understand, was she really Estonian or Russian? Her accent sounded Russian and in the movie they said she came from Russia, but the institute was in Estonia and the family she killed was Estonian. Was she posing as a Russian child? Also, how did she come to the US? They mentioned something about the Sullivans?