Help With A Harment Problem?

Hi, my mother has had this woman haring her for a VERY long time. She says threatening things when she sees my mother in public, she'll follow my mom's vehicle all the way to our house whenever my mom is on her way home, and she continuously calls our house (we don't answer the phone). She also made a fake Facebook about my mom, saying that she was a biual , who would do any ual favor you wanted for free. Last night, she called my house, and I answered the phone before I looked at the caller ID. She asked for my mom, and I told her that she couldn't talk to her. She started threatening ME, and told me I better watch my back now that I'm 18. I'm scared, but reporting her to the police doesn't do any good around here. We've tried. Also, she's very crafty, and ALWAYS comes up with an excuse to make her look innocent. I don't know what to do. We can't afford lawyers or anything to help us out, but I need to know if I have other options. Please.