How can I handle a mother who has become, bitter, rude and even more stubborn as she has aged?

My parents divorced a couple years ago. She thinks this divorce has only affected her life. She wants to be independent, but then complains if we don't help her. She won't listen to advice I give her. But if someone else gives her the same advice, she will. When I am around her, I have to watch my words carefully because one wrong word will set her off. She has isolated other life long friends as well, she wont seek help.. or go to church with me.. I'm not sure what advice I am seeking, maybe I just needed to vent.