Her husband drinks alcohol; should she stay with him?
Question

                My sister is married to a man who drinks alcohol and is virtually addicted to it. He also stays up at night a great deal. She got tired of advising him and asking him to give it up, and he refused to do so. Is it permissible for her to live with him knowing that she has two children from him. She is in another Arab country and is suffering from loneliness. What do you advise her to do, may Allaah reward you?.
Praise be to Allah.
    Firstly: we ask Allaah to help your sister to deal with this 
    calamity and to bring her relief, and to guide her husband to give up this 
    major sin in which he is persisting. 

    With regard to the ruling on her staying with him, it is 
    permissible for her to do so if she is certain that she and her children 
    will be safe. 
Shaykh Ibn ‘Uthaymeen 
    (may Allaah have mercy on him) said: I think that if she has advised him and 
    he has not responded, then she has the right to ask for an annulment of the 
    marriage. But there may be reasons why she cannot annul the marriage, 
    because she has children and annulment may cause further problems. If his 
    sin does not reach the level of kufr, then there is no sin on her if she 
    stays with him for fear of evil consequences. But if his sin reaches the 
    level of kufr, such as if he does not pray, then she should not stay with 
    him a second longer. 

    Al-Liqa’ al-Maftooh, Q. 518. 

    Secondly: Our advice to her is that she should weigh up what 
    is in her best interests, and consult her family and relatives, who know her 
    situation best. Then she should ask Allaah’s guidance (by praying 
    istikhaarah), for Allaah will never let her down. As the report says: No one 
    loses by praying istikhaarah and no one regrets consulting others. Whether 
    she chooses to annul the marriage or to stay, let her accept what Allaah has 
    decreed for her and be patient and seek reward. Allaah says (interpretation 
    of the meaning): 

    “but give glad tidings to As‑ Saabiroon (the patient)”

    [al-Baqarah 2:155]
And Allaah knows best.