Praise be to Allah.
It is narrated in the hadeeth that a recently widowed woman is not allowed to do five things, and that she is required to do five things.
1 – She should stay in her house where she was living when her husband died; this is the place where she should stay until the end of her ‘iddah, which lasts for four months and ten days, unless she is pregnant, in which case her ‘iddah ends when she gives birth, as Allah says (interpretation of the meaning):
“And for those who are pregnant (whether they are divorced or their husbands are dead), their ‘Iddah (prescribed period) is until they lay down their burden” [al-Talaaq 65:4]
She should not leave the house except in case of need or necessity, such as going to the hospital if she is sick or to buy things she needs from the marketplace such as food etc., if she does not have someone with her who can do that. If the house is destroyed, then she should move elsewhere, or if she does not have anyone to keep her company and she fears for her safety, then it is OK for her to leave if there is a need to do so.
2 – She should not wear beautiful clothes, yellow, red, etc. Rather she should wear clothes that are not beautiful, whether they are black or green, etc. What matters is that the clothes should not be beautiful, as this is the command of the Prophet (peace and blessings of Allah be upon him).
3 – She should avoid wearing jewellery of gold, silver, diamonds, pearls and the like, whether that is necklaces, bracelets or rings, etc., until her ‘iddah is over.
4 – She should avoid wearing perfume; she should avoid perfuming herself with bukhoor (incense) or any other kind of perfume, except when she purifies herself following her period, in which case she may perfume herself with a little bukhoor.
5 – She should avoid kohl; she may not apply kohl or any similar kind of cosmetic that is used on the face, the kind of cosmetic that may attract people to her. But with regard to regular beautification by using soap and water, that is OK. But the kohl which is used to make the eyes look beautiful and other kinds of cosmetics which some women use on their faces. This should not be done.
These are the five things which must be taken care of in the case of a woman whose husband dies.
But with regard to what some of the common people think and have fabricated, that a recently-widowed woman should not speak to anyone or speak on the telephone, or that she should take a bath no more than once a week, or that she should not walk barefoot in the house, or go outside in the moonlight, and other similar myths, there is no basis for these things. She may walk in her house barefoot or wearing shoes; she may do what she needs to in her house, cooking food for herself and her guests; she may walk in the moonlight in the courtyard and garden of her house; she may take a bath whenever she wants; she may speak to whomever she wants in a manner that is not suspicious; she may shake hands with other women and with her mahrams, but not with non-mahrams; she may take off her khimaar (head cover) if there are no non-mahrams present. But she should not use henna or saffron or perfume, either on her clothes or in coffee, because saffron is a kind of perfume. No one should propose marriage to her, but it is OK to hint, but clearly proposing marriage is not allowed. And Allah is the Source of help.
A fatwa of Shaykh Ibn Baaz, from Fatawa Islamiyyah, vol. 3, p. 315-316 .
For more information see al-Imdaad bi Ahkaam al-Ihdaad by Fayhaan al-Mutayri; Ahkaam al-Ihdaad by Khaalid al-Muslih .