Paying Zakat In Advance And Helping Parents, Children And Siblings With Zakat
In such cases of close relatives, parents and children, you can spend on them from your Zakat only after you have fulfilled the basic responsibility and some extra or unusual need arises to demand more from you.
Brothers and sisters are not legal responsibility like parents and children. What you do with them is favour. So, you can help them with zakat, rather, they have preference to others as they closer than others.