The benefit to her is having no real responsibilities, to gain sympathy...adults tend to be extra nice to disabled children, many dote on them & coddle them. The Barnett’s goal was for her to lead as normal of an independent life as possible. Like getting a job, cooking & cleaning, shopping, laundry etc. Natalia did not want to be an adult. Being an adult is HARD. I would imagine it’s EXTRA HARD for a dwarf.
Openly trying to kill them & doing other disturbing things - her goal was to get moved to the next unsuspecting family and try again. I suspect that worked on the previous adoptive parents.
Just as we can not say what Natalia really wanted or her goals, I don't think we can say that the Barnett's goal was as pure if, in fact, this child was actually a child and not the adult they forced her to be.
Do you know the Barnett family? Do you know any family this child lived with? Do you know her? I guess I wonder how you can be so sure that everything that has been written and spoken by the Barnetts is true and that Natalia is a monster. For me, I am taking the work of LE and seeing that they would not pursue this unless there was some fire beyond the smoke blowing toward them. I can say I have some doubts but I will never demonize a child but I always tend to believe that there is good in every child waiting to be uncovered.