Is speaking about the actions of a girl who died murdered, and who openly committed sins, for the purpose of drawing lessons and reminding of righteous deeds, considered unlawful and a violation of her honor?

The default is the obligation to refrain from slandering deceased Muslims and to avoid mentioning their bad deeds, based on the Prophet's (peace be upon him) saying: "Do not revile the dead, for they have gone on to what they have presented."

However, it is permissible to mention the faults of deceased individuals who openly committed evil, for a legitimate religious benefit such as warning and deterring others from their actions. This is supported by the hadith about praising or dispraising funerals and the Prophet's (peace be upon him) saying: "You are Allah's witnesses on earth."

Al-Nawawi held the view that it is permissible to mention the faults of deceased disbelievers. As for deceased Muslims who openly committed فسق (flagrant transgression) or bid'ah (religious innovation), it is permissible to mention their faults if there is a benefit, such as the need to warn against them or deter others from emulating them; otherwise, it is not permissible.