What is the ruling of Islamic law on how to deal with one's mother and her husband, and a corrupt family, while preserving one's children and family, and informing the husband of the truth of the matter without harming one's reputation?

Firstly: Conceal the faults of your family and do not spread indecency, for spreading it is among the gravest sins. And whoever conceals a Muslim, Allah will conceal his faults.

Secondly: Do not despair of their guidance. Supplicate for them, and enjoin good upon them and forbid evil from them with gentleness and respect.

Thirdly: Filial piety towards parents is obligatory, even if they are disobedient. There is no room for leniency in this regard, but there is no obedience to them in shirk (associating partners with Allah).

Fourthly: It is not permissible to expel the mother if she visits. Affection and kindness towards her are more conducive to treating her better than she was.