Estrangement between sisters-in-law

I have a sister-in-law who apparently has stopped speaking to several other members of her family over the years. We were pretty close, I liked her a lot. She and my brother had been married about 10 years and we got into a fight over the phone. She hung up on me, that was it. She refused to speak to me, done. To the point where if we were at a family gathering, she would make a point of not speaking to me or she would tell another family member to tell me something.

Finally, earlier this year, I had had enough. I sent my brother, her husband, a text message, telling him that I wasn't going to play her game any longer. He called me about 10 min later and put her on the phone. We talked for about 30 min. I was very direct about what had happened in the past but at the same time, told her more than once during the conversation that I was VERY appreciative of her calling.

It is now like those years never happened. She calls me from time to time. When I see her, it's like we are old friends. My brother says I am the only person he knows of that she has ever re-established a relationship with after cutting them off. So it's kind of strange, and I joke with her about it every once in a while, and tell her I should have told her to go to hell a few years ago...but it's great to have her back.