From the video it looks like she was off her medication.
I (no I'm not a doctor) tend to agree. I have a child with severe ADHD and possible bipolar (my mother had/has it so they think he might too we aren't sure yet). This girls behavior although more severe reminded me of my son. I am a 'strict' parent that does on occasion use a spanking as punishment if the 'crime' warrants it so my son never got that bad but I could easily be persuaded that another child without proper medical treatment, counseling and disclipline would most definitley get this out of controll. SO it may not be ALL (although I must say mostly) the mother's fault.....there very well could be a medical reason for at least some of the child's behavior.