The hardest thing in a conflict is to separate the person and the points she is making

This is easier said than done and I have failed many times in the past to make this separation

When we are engaged in a heated discussion with someone we tend to listen more with the intent of replying, than to understand her point of view. We bring things from the past and use them to fight in the present

We let our preconceived notions about the person cloud our judgement

The best thing to do in such a situation is to take a pause and ask yourself whether you are fighting the person or the points she is making. And respond to her points than her behavior (be it past or present). If you have been hurt by her way of speaking, something she did in the past, you can always bring that up later when the main discussion has ended

In this way you will prevent fights from getting dragged on and on, and also take the decision which is best for your relationship

I have read a lot of resources on this topic and here are some of the few which I found particularly helpful:

Books: Nonviolent Communication: A Language of Life, Crucial Conversations: Tools for Talking When Stakes Are High

Articles: Best reads on Firstround to deal with conflicts, 5 hard questions to ask yourself during a conflict, How to make a good argument, 5 steps for Disagreeing Effectively