Is it permissible for a working woman to pay zakat on her money from her salary without her husband's knowledge that she possesses this money?

A woman has an independent financial ذمة (dhimma) and can dispose of her wealth as she wishes, so long as she is an adult and of sound judgment. This is the view of the majority of jurists. As for the Malikis, they hold that her disposition by way of donation (tabarru') of one-third or less is permissible. If she exceeds that, her husband has the choice to either approve or reject it, citing the Almighty's saying: "Until they reach the age of marriage, then if you perceive in them sound judgment, release to them their property." (Quran 4:6) A woman must pay zakat on her wealth, even if her husband does not permit her, because giving out zakat is not a voluntary donation (tabarru').