Is it permissible for a woman to marry herself off, or to appoint a lawyer as her guardian, or to have a guardian who is not a member of her family, given that her family objects to her marriage to a man in his seventies, while she is convinced of him and desires chastity?

The guardian (wali) is a condition for the validity of the marriage contract (nikah (definition)). Without him, the marriage is invalid, unless he obstructs her by preventing her from marrying a suitable suitor. In such a case, she may refer her matter to the ruler (hakim) to marry her off or order her guardian to do so. It is not permissible for her to appoint a stranger to be her guardian. As for the customary public declaration through a wedding feast (walimah (definition)), it is not a condition for the validity of the marriage if the contract has been concluded, fulfilling its conditions and pillars, which include the guardian and witnesses.