How do you know if your boyfriend's mother doesn't like you??

I have known my boyfriend and his mother for almost 8 years. Me and my boyfriend have always been close and I think she knows how close we are. Heck, anyone would know that if 2 people are together for almost 8 years, they're bound to be. But about a year and a half ago, I moved in with him and his mother. When I first came, she had a very bad case of Shingles and so I helped her out quite a bit with whatever she needed help with and I still do to this day. I have never turned her down or ever argued with her or spoken a wrong word to her. Over a period of time, she's gradually became more and more distant. She doesn't talk to me hardly anymore. I've overheard her talking crap about me to her friend and heard her laughing at me. She's blamed me for her hardships and I know I'm not the cause. I've been nothing but good to her. She acts like she doesn't want me around or she doesn't like me one. Can someone please tell me the tell tale signs of when your boyfriend's mom dislikes you?