Is it permissible to pay Zakat monthly in advance? Does the intention for Zakat suffice for the wife's money and jewelry? Does the husband receive a reward for paying his wife's Zakat with her knowledge and consent?

It is permissible for one who possesses the nisab to expedite the payment of zakat before the completion of the hawl (one year). The intention (niyyah) at the time of payment is a condition for giving zakat. It is not permissible to pay zakat on behalf of someone else except with their knowledge and authorization. Any amount exceeding the obligatory zakat is considered a voluntary charity (sadaqa) and is not counted as zakat.