How can one forgive a teacher who caused deep psychological harm to the questioner and her sister in childhood, and who still suffers from the effects of a plea of injustice, despite the passage of years and the attempts of family and friends to persuade them to forgive?

What helps you to forgive this woman is to remember the encouragement of Islamic law to forgive those who do wrong and its promise of great reward, and that the woman has apologized, and it is not the character of the noble to reject an apology, and that in forgiveness there is good for you and for her, and that it increases you in honor, and it is a way to attain Allah's forgiveness and pardon.