I recommend that you, personally, first examine one of my self-help books (Forgiveness Is a Choice, The Forgiving Life, or 8 Keys to Forgiveness). See which you prefer. Then bring a copy of the chosen book to your therapist as you also retain a copy. Both of you can work systematically through the book that you choose. Given the therapist’s years of experience in the mental health profession, she should have no problem assisting you on your forgiveness journey.
For additional information, see Learning to Forgive Others.