In the argument, was she attacking you rather than making a rational case? You could name the dynamic next time, which means to say that she is attacking you instead of actually putting forth an argument. Let her know that it is a very dirty way to argue, or that it is damaging your relationship with her. It's also a logical fallacy. A lot of people will stop doing something once oyu name the dynamic.
Keep in mind that the advice I offer does not exclude the wonderful idea of acceptance. Acceptance doesn't mean that you condone it, nor does it mean that you still do not want to change it, acceptance just takes away your ego's investment in a particular situation. You can work on this in many ways, including working on yourself and working on your relationship with her.
