My husband discloses all our marital disputes to his family. What is the ruling of Islamic Law on this?
All praise is due to Allah, and peace and blessings be upon our master, the Messenger of Allah.
It is impermissible to divulge spousal secrets or expose one another's faults, whether during the subsistence of the marriage or after its dissolution. The foundational principle governing marital relations is that it is built upon confidentiality and mutual affection. Divulging marital secrets constitutes a breach of trust and a grave sin.
A husband ought not to resort to his family to complain about his wife over every dispute, nor is the reverse permissible for the wife, especially when such actions lead to stirring up malice and animosity between the spouses or between their respective families.
Islam has enjoined the preservation of secrets in general and commanded against revealing them; safeguarding the privacy of the home holds an even greater priority. And Allah Almighty knows best.
Is it permissible for a woman to observe voluntary fast without her husband's permission?
A woman is not permitted to observe a voluntary fast (nafl) while her husband is present without his permission.
Is the son of the sister by breastfeeding considered a mahram in Islam, and is it permissible for a woman to go for Hajj with him?
Everything that is prohibited by lineage is also prohibited by breastfeeding. The son of the sister by breastfeeding is considered a mahram, just like the son of the sister by blood, and it is permissible for him to be her mahram for Hajj and Umrah. And Allah Knows Best.
I`m a pious Muslim woman, but my husband isn`t, what should I do?
You should exercise patience, make supplication that Allah guides him to the straight path, and keep advising him kindly.