How should sister-in-law and sister get along?

You did your best, but in fact, in a big family, what should I do if you want to talk about your family? You don't need to thank her if you don't expect anything in return. Think of her as ignorant or incompetent and pity her. Who let her be your brother's wife and nephew's mother? What you have done is good for a big family, but not bad. Walking straight and far is a reasonable person. Be happy that you did the right thing! A clear conscience is an important aspect of your life benefit.