]Didn't she say this was because, although husbands were supposed to treat their wives well in general, it was really their perogative to treat them however they liked, and not for others to interfere? The husband was in charge, and it was not in a brother or son's place to challenge his authority when it came to how he wanted to treat his wife.

An example in Jane Austen's work is that Colonel Brandon's brother treated his wife Eliza very badly. He was cruel to her, and there is Brandon's mysterious hint that his brother's "pleasures were not what they ought to have been"--which meant presumably something very despicable. And this treatment of her "provoked" Eliza's own inconstancy, which led to their divorce.

One thing Colonel Brandon says is that Eliza had "no friend to advise her" because he had taken himself out of the country to India, to give that marriage at least a chance, and the elder Mr. Brandon had died shortly after the marriage. But what is not clear is what form the advice would have taken. It almost sounds like they might have advised her not to be unfaithful to her husband, rather than anything that would have truly eased the misery of her situation.