What is the ruling on my friends marrying women from among the People of the Book if her Muslim father authorizes the Muslim suitor to conduct the marriage contract, given that a Muslim does not undertake the marriage contract of a woman from the People of the Book?

There is no problem with the first fatwa if the woman is Muslim and her guardian is Muslim, as it is permissible to appoint a Muslim as an agent for the marriage of his daughter. There is no problem with the second fatwa regarding the impermissibility of a Muslim directly conducting the marriage contract of a Kitabiyyah (woman of the People of the Book). As for a Muslim acting as an agent in such a marriage, jurists differ on two opinions: The first is that the agent of the guardian must meet the same conditions as the guardian himself, and this is considered the sounder opinion. The second is that it is permissible for a Kitabi (man of the People of the Book) to appoint a Muslim to marry off his daughter. Accordingly, a Kitabiyyah woman is married off by her guardian from among her own people, or their priests, or a Muslim judge if they are not available. However, if a Muslim conducts her marriage, the contract is invalid and must be annulled. The child will be attributed to his father due to the doubt (shubha), and the contract must be renewed, fulfilling its conditions.