How should they deal with a relative of theirs who steals and consumes wealth unlawfully?
Question

                I am asking about the ruling on a woman staying with her husband who borrows money from others and does not pay it back or even apologize. He uses this borrowed money in projects with others and uses it for his own matters. This problem developed even to the worst; he started stealing from others directly from their pockets or making a copy of someone’s keys and stealing their valuable things. 

This man unfortunately deceives his wife and lies to her by saying that he repented while he still is doing the same evil actions. What should we, his relatives, do? We suffered a lot from his fraud and theft of our possessions. What should his wife, our sister, do? She refuses to leave him justifying this by saying that he is repenting and still is saying that there is no God but Allah.
Praise be to Allah.Firstly: 
Stealing, embezzling and 
    consuming people’s wealth unlawfully are all haraam actions, as is well 
    known. Stealing is a major sin because of the stern warning that is narrated 
    concerning it. al-Bukhaari (6783) and Muslim (1687) narrated from Abu 
    Hurayrah (may Allaah be pleased with him) that the Prophet  (peace and 
    blessings of Allaah be upon him) said: “May Allaah curse the thief, for he 
    steals an egg and his hand is cut off, or he steals a rope and his hand is 
    cut off.” 
And Allaah says 
    (interpretation of the meaning):
“And (as for) the male 
    thief and the female thief, cut off (from the wrist joint) their (right) 
    hands as a recompense for that which they committed, a punishment by way of 
    example from Allaah. And Allaah is All‑Powerful, All‑Wise”
[al-Maa’idah 5:38]
What the one who commits 
    such actions must do is repent to Allaah from that, and return the property 
    to its owners; his repentance is not complete unless he does that, because 
    the Prophet  (peace and blessings of Allaah be upon him) said: “Whoever 
    has done some wrong to his brother, let him seek his forgiveness today 
    before there is no dinar or dirham, when if he has some righteous deeds (to 
    his credit), some of his hasanaat (good deeds) will be taken in proportion 
    to his wrongdoing, and if he has no hasanaat some of the sayi’aat (bad 
    deeds) of the one whom he wronged will be taken and added to his burden.”
Narrated by al-Bukhaari 
    (6534). 
Secondly: 
The one who knows about 
    this man’s situation must advise him and explain to him the abhorrence of 
    his actions, and he should not despair of his repentance and being guided. 
    He should also warn those who have been deceived by him and want to deal 
    with him in business and the like. He should do that on the basis of 
    sincerity and wanting to do good, not on the basis of condemning or putting 
    him down. 
With regard to his wife, in 
    addition to the above, she must also beware of consuming the haraam wealth 
    that her husband acquires, because the Prophet  (peace and blessings of 
    Allaah be upon him) said: “Every body that is nourished from haraam wealth, 
    the Fire is more befitting for it.” Narrated by al-Tabaraani and Abu Na’eem 
    from Abu Bakr; classed as saheeh by al-Albaani in Saheeh al-Jaami’ 
    no. 4519 
If she knows that some of 
    the wealth is stolen or plundered, it is not permissible for her to benefit 
    from it. 
We ask Allaah to set our 
    affairs and those of the Muslims straight. 
And Allaah knows best.