بسم الله الرحمن الرحيم
(Fatwa: 899/733/D=11/1437)
It is not lawful to give zakah money to one’s maidservant as remuneration of her services. Yes, if you pay her salary and in addition give zakah money to her as reward then it is allowable. If the maidservant is sahib-e-nisab then your zakah shall not be paid if you give her your zakah. Hence it is not better to decide merely on conjecture rather you should ask the maidservant in person or enquire by some other means then go ahead accordingly. Some women apparently look poor but they own gold jewelry etc which makes them sahib-e-nisab, so it is necessary to enquire about it. However whatsoever zakah you have given in past thinking her poor it was paid and valid.
Allah knows Best!
Darul Ifta,
Darul Uloom Deoband