Is the sister's daughter eligible for Zakat, given that her father is deceased and her mother is employed and married?

If the sister is wealthy from her work or her money, enough to cover her daughter's expenses, then the daughter is not eligible for zakat (definition). Similarly, if the daughter is wealthy due to what she inherited, because zakat is not given to the rich. However, if the mother is poor and does not own enough to cover her daughter's expenses, and the daughter is also poor, then she is eligible for zakat. In this case, it is charity and an act of kinship, as the Prophet, peace and blessings be upon him, said: "Charity given to a poor person is charity, and charity given to a relative is both charity and an act of kinship."