Then maybe it isn't "Can't", but it also isn't yet "Choose not to"...
Could it be you "Don't know how" to forgive for what she has done?
Because in that case, that is what counselors/pastors etc. are here for! They help with that.
Sorry if I overgeneralize. That word "can't" just strikes a nerve with me. BC my WAH says often that he "can't" figure out how to have a future with me, he "can't" forgive and let go of the past.
I have a different opinion. It is more of a 'want' thing.
For example, I "can't" speak French.
No amount of wishing, praying, hoping, THINKING will suddenly make me speak French.
Because on a basic level, "I don't know how" to speak French.
However, if it were something I really desired, I would seek out a class, a tutor, rosetta stone or whatever to start learning.
Since I haven't, I would say that means I don't really want to do it.
So ultimately it becomes, "I don't want to speak French", or "I choose not to speak French".
Weird analogy but I hope you get what I am trying to say....
If someone cannot forgive, is it because they don't know how or they choose not to? It could be either, or both, ultimately.