It sounds like you could file a restraining order on her. You would need to know her address and then compile a list of harassment incidents such as what she has said on social media and her treatment of siblings and friends. You should include specific dates and details. You should also include the dates and details of when you have approached her to stop.
You can also request that witnesses (those who are over 18 years of age) attend the hearing.
Answered on Nov 14th, 2014 at 1:40 PM