What is the ruling of Islamic law regarding the severance of ties between a brother and his sister, who is married to a family that is in dispute with his family, and what is the ruling regarding the sister falsely accusing her brother through the media?

It is impermissible for a Muslim to abandon his Muslim brother for more than three nights. The better of the two disputants is he who initiates the greeting of peace. It is obligatory to hasten reconciliation between neighbors, in-laws, and kin to attain goodness and forgiveness, as Allah Almighty says: "And reconciliation is best," and He says: "There is no good in most of their secret talks save (in him) who orders charity or rectitude or reconciliation among people." The Prophet, peace and blessings be upon him, warned against abandonment in his saying: "The gates of Paradise are opened on Mondays and Thursdays, and every servant who associates nothing with Allah is forgiven, except a man between whom and his brother there is animosity. It will be said: 'Look at these two until they reconcile.'" Furthermore, severing ties with a sister or an paternal aunt is forbidden, because "a severer of ties will not enter Paradise." A sister's lying to her brother and his children is forbidden, as is her disowning them if she intends thereby to disown her lineage from them.