Their parents made bequests before they died stating that the estate was to be divided in a specific manner; do they have to follow that?
Question

                Our mother died last year but we didnt distribute the wealth as we wanted to keep everything for our farther as he might need it in future because no body knows about the time.

on 6th of Dull Hijjah our father passed away.

our mother wanted her jewelries to be distribute among her daughters (as we are three sisters and one brother)the house our brother is the nominee.

now we want to know how to distribute every thing according to Islam our according to our parents wish.our main aim is we do not want to do anything that either we or our parents will be accountable in front of Allah.
Praise be to Allah.If your father and mother 
    did not share out their estates when they were still alive, such that each 
    person took his share and disposed of it, then what they said is regarded as 
    a bequest (wasiyyah) and a bequest to an heir is not to be executed except 
    with the permission of the other heirs. 
If all the heirs agree to 
    the bequest, and they are adults of sound mind, there is nothing wrong with 
    that. But if they want to divide the estate according to the rules of 
    sharee‘ah, they have the right to do so, and they do not have to carry out 
    the bequest, because the principle is that it is not permissible to make a 
    bequest to an heir. If a bequest is made to an heir, it is not to be carried 
    out except with the consent of all the heirs, because of the report narrated 
    by Abu Dawood (2870), al-Tirmidhi (2120), al-Nasaa’i (4641) and Ibn Maajah 
    (2713) from Abu Umaamah who said: I heard the Messenger of Allah (blessings 
    and peace of Allah be upon him) say: “Allaah has given each person who has 
    rights his rights, and there is no bequest for an heir.”
The hadeeth was classed as 
    saheeh by al-Albaani in Saheeh Abi Dawood. 
It was also narrated by al-Daraqutni 
    from Ibn ‘Abbaas as “It is not permissible to make a bequest to an heir 
    unless all the heirs want that.” Classed as hasan by al-Haafiz Ibn Hajar in
    Buloogh al-Maraam. 
And Allah knows best.