Wow.
She sounds like a very lazy & incompetent Nanny for sure.
It is so weird that she would do all those things that you mentioned knowing full well that she was being filmed.
I guess add clueless to her characteristics too.
I know firing her will leave you high + dry until you find someone else, but I wouldn't want to leave my kids w/someone so lazy and uncaring.
Seems she sees childcare as easy money and considers your two children her little "ca$h cows."
Can you or your husband take some time off work to search for a replacement?
Perhaps you can contact a good domestic agency and find someone soon.
So sorry about this.
Good luck moving forward.