Very depressed about my daughter

I was reunited with my daughter and I am sad to say that things have gotten ugly. She is not the same person I met. She hid her lifestyle from me. I am heartbroken and distraught over what is unfolding before me. She hangs around low-lifes, and also has recently become a gang member and thinks it is honorable. This is a woman in her 40's with children at home. She has serious issues that I am ashamed to speak of. Her children(my grandchildren) are also troubled. My family wants nothing to do with her and advises me to keep away from her. I am so distraught over all this. I don't know what to do..