Is it permissible to give zakat to the son of a divorced sister to cover his education expenses, given that his father provides him with only a small amount, and his mother does not possess enough to meet these high expenses?

It is permissible to give Zakat to a poor sister whose income is insufficient to cover her basic needs. As for giving Zakat for school expenses, it is permissible only if it is not possible to enroll in free or less expensive schools.