All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.
You should not stop your financial support to your brothers and you should not take into consideration the discouragement of their wives from supporting them especially that they need your support. Indeed, one’s relatives are the most deserving of his kindness, and donating money to them combines two benefits, the benefit of giving to charity and the benefit of keeping ties with kinship. Salmaan Ibn ‘Aamir narrated that the Prophet said: “Giving charity to the poor is considered charity, and giving charity to a relative is two things: charity and keeping ties with kinship.” [Ahmad, At-Tirmithi, An-Nasaa’i, and Ibn Maajah]
Allaah Knows best.