I’m sure God would have some understanding for/ mercy on a victim or their close loved one having difficulty in forgiving.
He would not say it was right or just for them to act unforgiving though.
Their emotional state might be a mitigation of their sin of lack of forgiveness.
This isn’t a new issue. I found a copy of Sacred Heart Messenger at my mom’s. It’s over 100 years old and probably belonged to my grandma or great-grandma. The first story I read in it was about an elderly Irish mom’s difficulty in forgiving the soldiers who tortured and hung her son in front of her eyes, just for fun. Of course the ending (this being a Catholic magazine) has her forgiving the soldier, hiding him from an angry mob of her neighbors, and then dying in her sleep in her rocking chair with a happy smile on her face as she is reunited with her son in Heaven.
Forgiveness is very hard. We have to make our best effort anyway but it’s easier to talk about someone else doing it than do it ourselves in an awful situation.