You should probably be documenting this very carefully and thoroughly. Threatening you with false arrest is probably a crime.
I would, at the very least, get written statements from any witnesses to her false and malicious behavior. At some point such evidence might be sufficient for a restraining order. I certainly wouldn't just ignore such threats.
There appears to be a presumption, perhaps slightly justified, that the first person in a conflict to call in the police is the one to be believed. You may want to be that person.
I'm not a lawyer, but if this was happening to me I would be consulting one with the reasonable expectation that the transgressor would eventually have to cover my legal costs.
I’m covered as well as I can be without retaining a lawyer. We (my wife [her sister] and I) saved a lunatic voicemail she left about 6 months ago with various threats and bizarre statements.
I do have a couple of additional family members that would testify as to her veracity, mental stability etc.
Under the circumstances, a restraining order is essentially impossible.
Fortunately, she is supposed to be leaving the state in the next eight weeks and putting her house on the market. She owes her ex money she doesn’t have which is due in a couple of months. She needs to sell her house to pay him, and then she will have to go live with her other sister...far far away from us.
It also is good that my wife trusts me 100% and is behind me.
According to my police friends the first call to the police is frequently the perp.
WTell makes good points. Also remember, recording devices are your friends. Next time she makes such a statement, get it on tape.