All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad, ﷺ, is His Slave and Messenger.
Our advice to your wife is that she should fear Allah, obey you in what is right, and maintain good companionship with you. She must also properly cover her body and conceal her adornment from non-maḥram men. It is not permissible for her to wear tight, transparent, or decorated clothing that attracts attention.
Our advice to you is that you should treat your wife kindly, and deal with her using wisdom and gentleness. Strive to rectify her, teach her the matters of her religion, and strengthen her connection with her Lord.
You are also required to ensure that she observes the obligatory ḥijāb, in accordance with your responsibility over her, and you should not be negligent in this matter. Allah, the Exalted, says (what means): {Men are caretakers of women…}
Al-Saʿdī, may Allah have mercy on him, said in his tafsīr: “Caretakers over them by obligating them to fulfill the rights of Allah—such as maintaining His obligations, and preventing them from falling into wrongdoing.”
If there are righteous and wise individuals among her relatives, or righteous women among your relatives, then perhaps their advice to her will be more beneficial and have a better effect.
Lastly, seek help from Allah abundantly through supplication, for indeed He is Near and Responsive.
Allah Knows best.