Will God forgive the harm my brother's wife has caused, given her memorization of the Qur'an and attendance at lectures, especially since everyone is aware of her bad behavior and her prevention of my brother from visiting me?

Harming Muslims through speech, backbiting, or other forbidden acts are among the sins for which Allah has threatened severe punishment for the perpetrator. Therefore, the wife must fear Allah regarding her neighbor and cease her actions so that her good deeds are not invalidated due to this injustice. The husband must command his wife to fear Allah and restrain her from committing sin and disobedience; otherwise, he would be betraying the trust that Allah has placed upon him.