Orphan: First Kill

After the first movie " The Orphan " I was quite eager to know about the beginning of Esther, how she came up to be who she is- you know the stuffs you have in a origin film. But this doesn't seem to be like that at all.

First of all, the movie doesnt even begin from the beginning in Esther's perspective. She was shown to be in a mental hospital and doctors mention her to be the most dangerous patient ever (we dont know why and how she was called that). Why should we not know why she was a dangerous patient? It was the "first kill" after all.

I often had the feeling of her not being a mental patient but just a killer who likes to kill, at least at the first. I am also ignoring all the small inconsistencies that were spread throughout the film.