Sahih al-Bukhari Book 68, Hadith 85
We were forbidden to mourn for more than three days except for a husband.
The Prophet (ﷺ) said, "It is not lawful for a Muslim woman who believes in Allah and the Last Day to mourn for more than three days, except for her husband, for whom she should mourn for four months and ten days."
We were forbidden to mourn for more than three days for a dead person, except for a husband, for whom a wife should mourn for four months and ten days (while in the mourning period) we were not allowed to put kohl in our eyes, nor perfume our-selves, nor wear dyed clothes, except a garment of 'Asb (special clothes made in Yemen). But it was permissible for us that when one of us became clean from her menses and took a bath, she could use a piece of a certain kind of incense. And it was forbidden for us to follow funeral processions.