Time is a huge factor for me in the process of forgiveness. Particularly when the hurt goes very deep. It is not a process I can rush.
If you think of a physical hurt....like scrapping a knee, you can't rush the healing of that wound. I think our emotional wounds are like that too. With the knee, if you try to pick the scab off before it has healed, it simply opens the wound again and it bleeds. If you're patient and allow the scab to fall off in its own time, there is fresh new skin that has healed beneath it.
Perhaps the emotional and psychological wound is still too fresh. I think you'll find that the time will present itself at some point in the future and you'll realize that you have forgiven her. Not for her, but for yourself. It's hard to say how long that will take.
You deserve to be free from the trauma her mean spirited actions caused.....and I do believe you will be when the time is right.
gentle hugs
ke