What is a relationship but a contract? Yes there are emotions but essentially it is a contract. It's a horrible situation for her no matter what. Hope she is ok and hope it doesn't happen to her again even thought that's quite unlikely.
A contract! Fuck me.
So before they got together did they both sit down and determine terms of the relationship? Did they envisage what would be the recourse for early termination of the 'contract'? How about, did they make provisions for recourse when he gets drunk and wellies the shit out of her on the street.
This isn't simple it never is.
What if she has nowhere to go? What if her friendship group is the same as his and if she leaves him she'll have noone? What if she never completed schooling/held down a job because he has said to her "I'm a footballer and you will never have to work a day in your life while you're with me"?