I don't know why you feel that it's a flaw that you can't forgive her if what she did was so terrible? What was it? You don't want to talk to her again, I'm guessing you don't want to date her again. What's the problem, it might be better for her not to be forgiven and she can move on and forget about you. Sometimes hot chicks live a life without cosequences becuase they say sorry in such a sweet voice.
Me personally, I can't stay mad at people especially girls. I've let the same people f me over several times and still forgive them for it. That's no fun either. If you forgive her what happens then? She stays in your life, and ex's in your life are rarely a healthy thing.