A:
It is permissible
to give Zakah to kinsfolk such as brothers and their children if they are poor and needy, whether they are married or single. They take priority over others for the Hadith reported from the Prophet (peace be upon him) that reads:
Your charity to the poor is regarded as one good deed, but paying charity to your relatives is both charity and maintaining ties of kinship.
(Related by Imam Ahmad, Al-Tirmidhy and Al-Nasa'y and the wording is of Al-Tirmidhy who ranked the Hadith as Hasan [a Hadith whose chain of narrators contains a narrator of weak exactitude but is free from eccentricity and blemish])However, if the brothers are not needy or the brothers-in-law are rich, it is not permissible to give them Zakah because they are not of the categories of Zakah recipients and (Part No. 8; Page No. 373) the brothers-in-law should maintain their wives. However, if the brothers-in-law are poor, Zakah should be given to them, because they maintain their wives.May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.