There can be exceptions to what is in the handbook & handbooks can normally be changed at any time. Also, handbooks generally do not rise to the level of a binding employment contract & many times there is a disclaimer in the handbook stating this.
Used cars are generally sold "as is" & it's buyer beware unless you are told different by the dealer/seller or have a warranty to the contrary. Always have a vehicle checked out by a mechanic of your choice before purchasing.
I don't know who you are but if you want to help her, you can suggest to her that she call the police if physically abused or CPS. You might also suggest she talk to a trusted adult such as a favorite teacher or school counselor.