When is it obligatory to pardon and overlook and to repel evil with good, and when is it obligatory to hold the aggressor accountable and complain against him, especially in the case of continuous injustice from a person who fights with falsehood and affects one's reputation and work?

The default is that forgiveness is better, but it is permissible to defend oneself and retaliate an evil with its equivalent. In this specific case, it is necessary to ward off harm from oneself and expose the falsity and slander of this woman to repel harm and remove injury, and so that no ill-will is thought of you, or people are deceived by her.