"It is not permissible for a woman to mourn for anyone who dies for more than three days, except for her husband." (Using translation from Nasāʾī 3525)  

عَنْ رَسُولِ اللهِ ﷺ قَالَ «لَا يَحِلُّ لِامْرَأَةٍ أَنْ تُحِدَّ عَلَى مَيِّتٍ أَكْثَرَ مِنْ ثَلَاثٍ إِلَّا عَلَى زَوْجِهَا»  

"It is not permissible for a woman who believes in Allah and the Last Day to mourn for more than three days, except for her husband." (Using translation from Nasāʾī 3526)  

أَنَّ رَسُولَ اللهِ ﷺ قَالَ «لَا يَحِلُّ لِامْرَأَةٍ تُؤْمِنُ بِاللهِ أَنْ تُحِدَّ فَوْقَ ثَلَاثَةِ أَيَّامٍ إِلَّا عَلَى زَوْجٍ»