do you have a friend to whom you know very well

I have a friend whom I know well. We've been friends for 20 years or more. Our kids grew up together. We're not just friends, we're like sisters. I'm so proud of her and I'm so lucky to have her as a friend. Though we do have aabout 9 yrs age difference. She was able to bear my childishness, I'm younger than her. Many had tried to break our friendship but they all failed.