Is it permissible to give zakat al-mal to one's sister to furnish her marital home, knowing that the father is deceased and his pension is insufficient, and the brother covers the expenses for food and drink?

Maintenance for relatives is obligatory only for ascendants and descendants. Therefore, maintenance for siblings is not obligatory. If the deceased father's salary is insufficient for their needs, it is permissible to disburse Zakat to them to cover marriage expenses and bridal preparations, provided that it does not exceed basic necessities and extends to luxuries.