Praise be to Allah the Lord of the Worlds.
The woman whose husband has died must stay at marital home until her Iddah expires. Moreover, that she must stay overnight in her home is attested to in the following Hadith: Furai'ahbint Malik, the sister of Abu Sa'eed Al-Khudri, said: "My husband died in Al-Qadum, so I went to the Prophet and told him that our house was remote." He gave her permission then he called her back and said: "Stay in your house for four months and ten days, until the term prescribed is fulfilled." {Sunan `An-Nasa`i}. However, the learned men of the Islamic faith have excluded moving to another house, while observing Iddah, in case of necessity: she feared for her life or couldn`t afford the rent and the like. Al-Shirbini says: "The woman who is observing Iddah following her husband`s death is allowed to move from marital home for an excuse, such as fearing for her child or wealthfrom flood or demolition." {Moghni Al-Mohtaj, 5/107}.
In addition, it is well known that no maintenance is due to the woman whose husband has died, whether she is pregnant or not, because she is entitled to inheritance. This is attested to by the Hadith in which the Prophet (PBUH) said "The woman is still entitled to provision and shelter if the husband can still take her back.'"{An`Nasaa`i}.
Zakaria Al-Ansarie (May Allah be pleased with him) said: "No maintenance is due to the Ba`in-divorced, non-pregnant woman, even by judge`s ruling or death of husband, because the latter has no authority over her anymore. And the same ruling goes for the pregnant whose husband has died." {Fateh Al-Wah-Haab, 2/145}.
Article (154/A/2010) of the Jordanian Personal Status Law states, "No maintenance is due to the woman whose husband has died, whether she is pregnant or not."
However, if your(Asker) brother (son of the deceased) wanted to take his house back and didn`t renew the rent contract for his mother-in-law then she is permitted to complete her Iddah at her family`s out of necessity. We advise your brother to treat her kindly and allow her to stay there until her Iddah expires. Also, her husband`s sons should serve and help her as part of honoring their father since the Messenger of Allah has encouraged this noble act in the Hadith where he said, "The finest act of goodness on the part of a son is to treat kindly the loved ones of his father." {Muslim}.
As for the estate of the deceased (Money, property or furniture), it must be divided amongst the eligible heirs as commanded by Sharia. However, if the furniture is part of the wife`s Maher then it is hers. If it isn`t then it must be divided amongst all the heirs and the wife has no right to demand any extra amounts other than her lawful share. And Allah the Almighty knows best.