Please help me to see if the relationship between my wife and her brother-in-law is normal. My wife and I were introduced and have been married for almost three years. Found a wife after marriage
This is not normal. Generally speaking, my sister and brother-in-law are like an ordinary family, but as you said, she is too dependent on her brother-in-law and doesn't even listen to your advice, so they are definitely different. You can tell her sister, after all, that's her husband. Ask her sister if she found anything unusual!