Is it permissible to count the monthly portion given to needy siblings (for medical treatment, education, or living expenses) as part of the annual Zakat on money?

It is permissible to give zakat to poor or needy siblings, and this is more virtuous than giving it to others, as it is both charity and maintaining kinship ties. It is permissible to pay zakat in installments in advance during the year, but it is not permissible to delay it after the year has passed.