All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His Slave and Messenger.
Marrying an insane woman is valid as long as marriage meets the conditions of validity. If your wife is mentally disturbed, perhaps what she says is due to her insanity. So, you will have a great reward if you keep her as your wife, for this will cover up her sins and maintain her chastity. If her madness and infertility harm you, then we still advise you to keep her as a wife and marry another woman. You should advise her according to the limits of her mental capacity.
On the other hand, if she is mentally sound while revealing her sins proudly, you should advise her and frighten her with the Punishment of Allaah The Almighty. She may repent as a result. However, if she insists, divorce her, knowing that there is no need to inform her family why you divorced her. Unless there is someone who can affect her, you can inform only him of her attitude for the sake of giving her some advice. The Prophet, sallallaahu ‘alayhi wa sallam, said: “Whoever covers up (the faults of) a Muslim, Allaah Will Cover him up (his faults) on the Day of Judgment.” [Al-Bukhari]
Allaah Knows best.