Is it permissible for brothers to ostracize their divorced sister who married a man who is not her equal, and without their consent, or is that considered a severing of family ties?

For a marriage to be valid, the presence of a guardian (wali) and two just witnesses is required. However, some imams have permitted a woman to عقد her own marriage contract. If the contract was concluded in court or by an authorized marriage official (ma'dhun), then it is valid. The ruling on what the woman did depends on the condition of the husband: If he is suitable (kafu') – a chaste Muslim who is not openly defiant of Allah's commands (fasiq) – then her family is not permitted to prevent her from marrying him under the pretext of age or social status. She has the right to resort to the judiciary to facilitate her marriage, and her family is not allowed to abandon her. However, if the husband is unsuitable (ghayr kafu') – an innovator (mubtadi') or an openly defiant person (fasiq) – then the family's objection is valid, and her insistence on marrying him makes her disobedient. Nevertheless, the family is advised not to abandon her and to work towards her reformation and that of her husband, especially since the marriage has already taken place.