Quoting Mary Foley, who forgave the girl who killed her teenage daughter:
Forgiveness did not come immediately, even after I knew it was what I wanted. It was hard. My main struggle was seeing Charlotte being stabbed in my imagination, and knowing that I hadn't been there to help her. I often envisaged her bleeding to death. When I saw these things in my mind, the old anger would begin to rise up in me, and I had to remind myself why I had chosen to forgive: so that I could release all that pain and hurt into the hands of God.
Source: Johann Christoph Arnold - Why Forgive?, pp.74