Is the mother considered disobedient if she does not forgive her brother who molested her 8-year-old daughter, especially since her mother insists on forgiveness, claiming he is young (16 years old), and does forgiving him guarantee the daughter's safety, and does this constitute condoning evil and disobeying God?

If the brother repents and signs of repentance and righteousness become apparent in him, then it is not permissible to boycott him, because repentance erases what came before it. However, if his repentance does not become apparent and boycotting him is a means of deterring him, then it is not obligatory to obey the mother in maintaining ties with him. But if maintaining ties with him is more beneficial for his reform, then it is obligatory to maintain ties with him, with extreme caution and without allowing him to be alone with the daughter. Forgiving him is not a sin, but the sin is enabling him to commit forbidden acts or remaining silent about them.