Is it permissible to give zakat to one's fiancée to help her cover the expenses of marriage, given that she is indebted for half the value of a house she purchased, and I am covering her marriage expenses because she is an orphan?

It is permissible to give Zakat to a poor girl to help her prepare herself (for marriage) in a befitting manner, if she is unable to do so, or to pay off her debt if she is a debtor and unable to fulfill her obligations. However, if she is capable of preparing herself or paying off her debt, then it is not permissible to give her Zakat, unless there is another entitlement.