Is the marriage of a girl to a committed young man, with the help of the young man's friend acting as her guardian without her parents' knowledge, valid or void, in the event that the mother refuses due to her desire to marry her daughter to her uncommitted cousin?

A woman is not permitted to delegate someone in place of her guardian (wali) unless the guardian explicitly authorizes her to do so. A marriage without the guardian's permission is invalid. Furthermore, the mother does not have guardianship (wilayah) and cannot prevent her daughter from marrying a suitable partner, nor can she force her to marry someone she does not desire. What was done without the guardian's permission is void and must be renewed with his consent.