So we got to find out where the bot was from(sort of) so heres the 2 places i see the backstory of the bot could go

1. She is/was suposed to be a weapon for god knows what(i mean she can and will kill ,and do so quite quickly, while just going against the laws of robotics)

2. Not actually a advanced ai:

Some people just grabbed a girl off the street and shoved her conciousness into a robot body for unknown reason, (the reason she acts so robotic being purposefull limitations put on her so that she is easier to controll, like locking pieces of her away)