Praise be to Allah, the Lord of the Worlds; and may His blessings and peace be upon our Profit Muhammad and upon all his Family and Companions.
If a woman’s husband dies, she has to stay in the house where she was staying before the death of her husband, and should not go out except for a necessity and then she has to return home.
This is for all the waiting period which is 4 months and 10 days if she is not pregnant.
Allah Says (interpretation of meaning): {And those of you who die and leave wives behind them, they (the wives) shall wait (as regards their marriage) for four months and ten days, ….}[2:234].
If a woman is pregnant, she has to wait until she gives birth to. Allah Says (interpretation of meaning): {….And for those who are pregnant (whether they are divorced or their husbands are dead), their 'Iddah (prescribed period) is until they deliver (their burdens),….}[65:4].
Therefore, if your sister is not pregnant, then what one sister told her is true. Because only one month and a half nearly expired from the waiting period, and she has to wait for another month or so.
She has to spend the remainder of her waiting period in the house where she was staying even if she is on the condition that you have mentioned.
Ashab al-Sunan, Malik and Ahmad reported from the Hadith of Abu Said Al-Khudri that when his sister’s husband passed away, she went to the Prophet (Sallallahu Alaihi wa Sallam) and told him: ‘O Prophet (Sallallahu Alaihi wa Sallam) of Allah, my husband died, and I am living in a home that was faraway from the home of my family and brothers. He did not leave any money (wealth) for me to spend, I did not inherit any wealth, and he did not have a house, so if you give me permission I will join my family and my brothers’ house. I like it and it is better for me to fulfill some needs’. The Prophet (Sallallahu Alaihi wa Sallam) replied: “You can do so if you wish”.
She said, ‘I was happy and comforted that Allah has ruled on me by the tongue of the Prophet (Sallallahu Alaihi wa Sallam)’. (This was before the revelation of the verse concerning the waiting period that a divorced or widowed woman has to observe before she can marry again).
But while I was at the mosque or in one of the rooms, the Prophet (Sallallahu Alaihi wa Sallam) called me and said, “What did you say earlier?” She reported the story to the Prophet (Sallallahu Alaihi wa Sallam) then the Prophet (Sallallahu Alaihi wa Sallam) said: “Stay in your house in which you got the news of the death of your husband until the prescribed waiting period finishes”. She said: “So, I stayed in that home four months and 10 days”.
But a woman, during this period, can go out of her house during daytime to fulfill her necessities like buying food or anything else for her or for her children.
Allah knows best.
