How can one reconcile between a husband and his family who seek to separate the spouses, and what is the expiation for mistreating the husband after his patience and good treatment?

If the husband is righteous and treats his wife well, then he is a blessing that warrants gratitude to Allah. The brothers' attempt to divorce their sister from her husband is a great evil and injustice, and it is an act of sorcerers and devils. It is not permissible to obey them in this. The wife should explain to them the prohibition of their action and warn them of the consequences of injustice. If they do not desist, she may report them to the authorities, or she may live far away from them in a safe place that her husband approves of. The wife must treat her husband well and obey him in what is good, and she must repent to Allah for any previous shortcomings towards him, by ceasing the sin, regretting it, resolving not to return to it, and seeking his forgiveness, while striving to be a good wife and increasing in acts of obedience.