An adult sister of mine,is verbally/emotionally abusive towards our elderly parents.She lives with them and terrorizes them with insults,RAGES that last for hours,accuses them of things,threatens them,calls them names

,wants money from them,.
It is awful.She sounds like the devil herself.She will go into rages,say crazy off the wall untrue things,pedastalize herself as the best child they ever had.She has a grand sense of superiority,and entitlement.She has stole my belongings,claiming they are hers.She has attcked me physically,sending me to the emergency room.She cause great anxiety and pain and problems in the household.I dont knw why my parents havent called the police and either have her arrested,removed from the property with her belongings,and filed a restrianing order against her.
In public she puts on a different persona,holding realtives hands,kissing people,telling people she loves them.Inside the house,behind closed doors,she starts her terrorizing,threats,hurtful hateful untrue things she will accuse them of.She runs to relatives,and about anyone who will listen,accusing my parents of not treating her goodof FAVORING HER OTHER CHILDREN..Yes,this is a VERY ADULT WOMAN,,not a 5 year ld.She hangs great guilt and fear onto them.And quite the opposite is true
.Our parents have gone through great lengths to make life great for her..And they treated her MORE THEN JUST NICE,they treated her grand.I think she has Histrionic PD and Narcisstic PD..What now?How do we get this to stop?Ultimatum?Does that work with narcissit and histrionics?She doesnt think an thing is wrong with what she does.She justifies it as no ne did what she wanted or said. (????)She is OK until you cross her,,cross her and your screwed.need help!!