One of the wives is seeking the help of unjust laws to cause harm to the other wife; what is the ruling?
Question

                I am the second wife of a righteous man, and I love him very much. Since weve got married, his first wife has thrown him out, and demands to be divorced. She has a terrible temper and jealosy, which makes it basicly impossible for her to accept this marriage. She demands him to divorce me, and he does'nt have the niya to do this. She has asked the kafir government for help, and even the police.

When she accepts, she says that she will have 3 days, and I will have 1 day . My husband works 8 hours a day so this gives me basically 8 hours with my husband before he has to go to her for her 3 days again.

Sometimes she puts the condition of me having 1 day and she has to have 2 days and my husband wants me to accept this so that she doesn't divorce him. its hard for me as my heart is not content with this. I have given up so many rights as it is so that she might come back to him. She says that he has kids with her therefore she has right to more days. wallahi this is opression . I dont have any other option than accepting this in order for her not to divorce him. what advice could you give me? it hurts so much. Many brothers have been tested with divorce, and if that is his qadr he should accept it. oppressing my rights will not give him sweetness in his first marriage.
Praise be to Allah.
    Firstly: 

    Undoubtedly if one of the wives, whether it is the first wife or otherwise, 
    strives to bring about the divorce of the other wife, that is haraam and is 
    striving for the sake of falsehood, and for that which angers the Most 
    Merciful and pleases the Shaytaan. This comes under the heading of 
    covetousness and selfishness. Allah, may He be glorified and exalted, says 
    (interpretation of the meaning): “And 
    whosoever is saved from his own covetousness, such are they who will be the 
    successful” [al-Hashr 59:9]. 
    This indicates that the one who is motivated by covetousness and pursues his 
    whims and desires is a loser. 
It 
    also comes under the heading of thinking negatively of Allah, may He be 
    glorified and exalted, and of weak faith in His will and decree, for all 
    provision is in the hand of Allah, including the love of a husband for his 
    wife, the time he spends with her, and his interest in her. All of that is 
    included in the provision that is granted by Allah, and that which is with 
    Allah cannot be attained by disobeying Him. 

    Al-Bukhaari (5152) and Muslim (1408) narrated from Abu Hurayrah (may Allah 
    be pleased with him) that the Prophet (blessings and peace of Allah be upon 
    him) said: “It is not permissible for a woman to ask for her sister to be 
    divorced so as to deprive her of what is rightfully hers and take it for 
    herself; rather she will have what has been decreed for her.” 

    Ibn ‘Abd al-Barr (may Allah have mercy on him) said:  

    From this report we understand that it is not appropriate for a woman to ask 
    her husband to divorce her co-wife so that she can have him to herself; 
    rather she will have what has already been decreed for her, and the divorce 
    of her co-wife will not detract anything from that which has been decreed 
    for her, or add to it. 

    Al-Akhfash said: It is as if he meant that she seeks to deprive her of her 
    husband’s goodness so that she can have it all to herself.  

    Abu ‘Umar said: This hadith is one of the best hadiths about the divine 
    decree, according to the scholars who have knowledge of the Sunnah. It 
    indicates that no one will obtain anything except that which has been 
    decreed for him. 

    Allah, may He be glorified and exalted, says (interpretation of the 
    meaning): “Say: ‘Nothing shall ever happen to us 
    except what Allah has ordained for us’” [at-Tawbah 
    9:51]. 
    So this matter is quite clear to the one whom Allah has guided, praise be to 
    Allah.

    End quote from at-Tamheed (18/165) 

    Al-Haafiz Ibn Hajar (may Allah have mercy on him) said: 

    This indicates that it is emphatically prohibited for a woman to seek the 
    divorce of a co-wife, and emphasises that she should be content with 
    whatever Allah has decreed for her.

    End quote from Fath al-Baari (9/127) 

    Secondly: 

    Undoubtedly her efforts to harm her husband, and her seeking help from the 
    kaafir police against him are also obviously haraam. It is not permissible 
    for a woman who believes in Allah and the Last Day to do such a thing, which 
    is the result of the Shaytaan toying with her. 

    The same applies to her efforts to cause harm to her co-wife with regard to 
    division of the husband’s time, and to make the husband give her less than 
    is her right, or to make him incline towards the first wife, either for fear 
    of her efforts to seek divorce from him, relying on the kaafir laws that 
    will help her to do that, or to put pressure on the husband because of his 
    children, or other similar reasons, or abusing other weak points that she 
    sees in her husband and is exploiting in order to get something that is not 
    permissible for her, such as her husband being more inclined towards her or 
    favouring her with regard to division of his time, or trying to bring about 
    the divorce of her co-wife. 

    The Messenger of Allah (blessings and peace of Allah be upon him) said: 
    “Whoever harms others, Allah will harm him, and whoever causes hardship to 
    others Allah will cause hardship to him.”

    Narrated by Imam Ahmad (15755), Abu Dawood (3635), at-Tirmidhi (1940) and 
    Ibn Maajah (2342); classed as saheeh by al-Albaani. 
It 
    is not permissible for the husband to respond to her covetousness or her 
    wishes; rather he must strive to treat his wives equitably as much as he 
    can. However we do not think that he should let the matter go as far as 
    divorce; rather he should try to ward that off and put things straight, and 
    he should be keen to keep his wife and look after his children, and spare 
    them from living without a father, especially in that kaafir land. 
If 
    it is not possible for him to treat his wives equitably, because of the 
    circumstances mentioned, or for other reasons that may prevent him from 
    doing that, then we do not advise you to let your relationship with your 
    husband reach the level of all or nothing, by saying “Either me or her”, or 
    “Either give me my rights in full or divorce me,” or “Either this or that,” 
    and so on. 

    Rather the wise person tries to achieve the best of two options and ward off 
    the greater of two evils, to achieve whatever he can of that which serves 
    the best interests and ward off whatever he can of harm, to the best of his 
    ability. 

    Undoubtedly staying with a husband whom you love and he loves you, and who 
    finds comfort in you and you in him, even if that is once every three or 
    four days, is better for you than striving to seek divorce and live without 
    a husband, especially in a country like yours. 

    The worst-case scenario is: imagine if your husband had four wives, not just 
    two, what would you do? Would you ask him to divorce all his other wives, so 
    that he would have more time for you, as his first wife is doing? Or what 
    would you do? 
Be 
    tolerant with your husband and give him a break, so that he can manage the 
    situation and solve the problem, for kindness is never introduced into a 
    thing but it makes it more fair-seeming, and it is never removed from a 
    thing but it makes it ill-seeming. When Allah wills good for the people of a 
    household, He introduces kindness among them, and if He wills ill for them, 
    He removes kindness from among them. Faith is based on two strong 
    foundations: patience and tolerance. Patience enables a man to bear what he 
    faces of the pains and troubles of life, and helps him to cope with 
    religious duties, and to resist the whims and desires of the self and 
    natural impulses. 

    Through tolerance one will be able to show one’s good side and will be able 
    to resist whims and desires, and will strive to purify oneself and increase 
    one’s faith. 

    May Allah make things easy for you, set things straight between you and your 
    husband, suffice you against the evil of that which is worrying you, and 
    reconcile you and your husband on the basis of the best of that which Allah 
    loves and is pleased with. 

    And Allah knows best.