Back story: my sister has been lying and manipulating everyone around her for years. Lying about being raped, lying about my other sister to keep me from finding out she lied about being raped, and more recently she kicked her husband out and lied that he cheated on her, gave her herpes, impregnated his new girlfriend while they were still together (according to her, the girlfriend was pregnant for 13 months before giving birth) and she’s been keeping her 8 year old some from his entire family. His dad, who has a separation agreement that SHE WROTE with his visitation weekends listed but she refuses to let him see his son. She also won’t let me, my other sister or her sons grandparents see him. I know this because he found a way to FaceTime me on his iPad and told me he had been begging to see me and my daughter (his cousin) for months and she wouldn’t let him. He then got caught FaceTime talking to me and got in trouble for it. I haven’t heard from him since as she took his phone away and now his iPad. Anyway, she also drinks vodka from 9am until she goes to sleep, she neglects her son, and had her friend who also smokes pot and drinks all day living with her, and her friend beats her kids. Literally she is extremely abusive even to her husband. Anyway, I spoke to her ex to check on my nephew since he got in trouble for talking to me and I was worried about him and when I did I found out all the lies she was making up about him and that she was telling him she would have their son lie and say he is abusing him and has made multiple false CPS reports on him, all have come back with nothing found. Well apparently she found out I talked to him or something because she is now texting my boyfriend threats of calling CPS stating i do drugs (which I don’t, I’m pregnant and can’t even drink) that were in an abusive relationship, which we are not, we had one incident back when we were both 19 and 20 and we are now 25 about to be 26 and 27 but there was no harm and no charges pressed and it never happened again. She is also saying that we can’t properly care for my child which is untrue she is happy, healthy, and well cared for. I know I have nothing to worry about but I also don’t want her using false CPS reports to bully me like she has been doing to her ex. Any advice on how to handle someone like this?

Edit:

The only reason I have not filed a report on her yet is because she is already in a custody battle that she will likely lose and i have offered to testify at the custody hearing to help her ex get custody of his son, but my nephew is already going through so much that i wanted to try to let his dad handle it without uprooting him and putting him in a nasty CPS battle since he is already in the middle of a nasty divorce with a malicious mother who will do anything to hurt everyone around her even if it is hurting her son. His dad has so much evidence of what she’s doing that he should easily get custody it just takes some time with the courts (which has already begun)