Is it permissible to give zakat to one's daughter and her poor husband who cannot afford the marriage expenses, in order to help them furnish the house and cover the wedding party?

Zakat is given to cover the normal, non-extravagant costs of marriage, to the extent of need. The wife is not given from Zakat because her maintenance is obligatory upon her husband if he is able to provide it, or upon her guardian if he is not. However, if the husband is unable to provide her maintenance, then it is permissible to give her Zakat.