She died and left behind a husband, children and parents who are not Muslim
Question

                My wife died leaving me [the husband]a girl and 2 boys.She also has 3sister which 1 of them is a christian,2brothers 1 is also a christian,and a father and mother who also are not muslims.

How do I share her wealth,what is the ratio i am to use in calculating each share to be allotted to the beneficiary.
Praise be to Allah.
    If the wife was Muslim, no one can inherit from her except 
    her Muslim heirs, because of the reports narrated by al-Bukhaari (6764) and 
    Muslim (1614) from Usaamah ibn Zayd (may Allah be pleased with him), 
    according to which the Prophet (blessings and peace of Allah be upon him) 
    said: “A Muslim cannot inherit from a kaafir and a kaafir cannot inherit 
    from a Muslim.” 

    Shaykh al-Islam [Ibn Taymiyah] (may Allah have mercy on him) 
    said: The Muslims are unanimously agreed that a kaafir cannot inherit from a 
    Muslim and a kaafir man cannot marry a Muslim woman. End quote from 
    al-Fataawa al-Kubra (3/130). 

    So her estate is to be divided as follows: 

    The husband (which is you) gets one quarter, because of the 
    presence of descendants of the deceased (the children). Allah says 
    (interpretation of the meaning): “but 
    if they leave a child, you get a fourth of that which they leave after 
    payment of legacies that they may have bequeathed or debts” [al-Nisa’ 
    4:12]. 

    The rest goes to the daughter and two sons, with each male 
    getting their share of two females, because Allah says (interpretation of 
    the meaning): “Allaah commands you as regards your children’s 
    (inheritance): to the male, a portion equal to that of two females” 
    [al-Nisa’ 4:11]. 

    Her Muslim brother gets nothing, because he is deprived by 
    the presence of a male child. 

    Her non-Muslim father and mother do not get anything, as 
    stated above. 

    In order to divide the estate among the heirs, it should be 
    divided into 60 equal parts, of which the husband gets 15, each son gets 18 
    and the daughter gets nine. 

    If the wife was not Muslim, then no one can inherit from her 
    except those who followed the same religion as her. 

    And Allah knows best.