this doesn't really make sense to me though. How come her brother and sisters don't know about it? plus, how come when the fire happened at the party she was only "natasha" for like two minutes? usually people go on for weeks or even years before they remember who they orignally are. kanya remembered throwing the drink but not why. people with this disorder don't have any recollection of anything.
you can't really treat muliple personality disorder because the person suffering doesn't remember becoming that person or alter ego.