Inheritance question
Question

                In light of Quran and sunnah could you please provide information about inheritence in the following situation.

A father has 4 sons and 3 daughters. 1 son dies during the fathers life. Soon afterwards the fathers wife also dies leaving behind some of her own personal property? My questions are: 

1) How is the mothers property shared.

2) How will the fathers inheretence be shared once be passes away in particular with respect to the dead son? The dead son has left behind 2 wives (1 son from the first wife and 3 sons from the second wife). Will the children of the dead son be entitled to anything?.
Praise be to Allah.
    The question mentions “the father’s wife” and later on “the 
    mother.” As the ruling will vary, we will answer the question in such a 
    manner as to address both possibilities. 

    1 – Division of the estate left by the dead son: 

    His two wives get one-eighth, to be divided equally between 
    them. 

    His father gets one-sixth. 

    If the woman referred to in the question was his mother, she 
    gets one-sixth; if she was his father’s wife, she is not his mother and does 
    not have any share. 

    The rest goes to his four sons to be shared out equally 
    amongst them. 

    2 – Division of the estate left by the father’s wife or the 
    mother. 

    If she was the wife of the father and had no children – 
    either from her current husband or from another if she had been married 
    before – then her husband gets one half. The questioner has not told us 
    about the rest of her heirs so we cannot state how the rest of the estate is 
    to be divided. 

    If she had children – either from her current husband or from 
    another – then her husband gets one-quarter. The questioner has not told us 
    about the rest of her heirs. 

    If she was the mother, then her husband gets one-quarter, and 
    her children who were alive at the time of her death get the rest, with the 
    males taking twice the share of the females. 

    3 – Division of the estate left by the father. 

    His wife – if he had a wife – gets one-eighth. 

    The rest is to be given to his children who were alive at the 
    time of his death, with each male taking twice the share of a female. If he 
    did not have a wife, all his estate goes to his children, with each male 
    taking twice the share of a female.  

    With regard to the children of the son who died before him, 
    they do not inherit anything from their grandfather or grandmother. The fact 
    that the son would have inherited if he were still alive does not mean that 
    his share is given to his children if he dies, because the children in this 
    case are prevented from inheriting by the presence of their paternal uncles. 
    This is according to scholarly consensus. 

    And Allaah knows best.