What do you think of my sister's angry statement, "Religion is detailed for men," and her claim that women's rights in Islam are unclear? Does this put her outside the fold of Islam?

If the sister means by her statement: "Religion is detailed for men" that Allah has wronged women in His rulings or generalized them to subject them to injustice, then this is a sign of the disappearance of faith, and is considered one of the nullifiers of faith. This is because whoever hates anything that the Messenger of Allah, peace and blessings be upon him, brought, disbelieves; as Allah Almighty says: {That is because they disliked what Allah revealed, so He rendered their deeds worthless}.

It is necessary to strive to correct this erroneous understanding by informing her of the truths of religion related to women, and by seeking help from specialized books on this topic.