I agree that breast torture is the way to go to break her. She does not sound like she is very experienced so you can't burn her breasts or such, so will have to stay with the beating & rough handling. Pull those nipples til they are really stretched, that will get her attention.
Hard slapping, really hard til they turn red is another option. She will realize that being fucked by you will be more desirable than her tits being mauled & in agony.