My 15 year old niece is very clever; but she refuses to attend school, has an older boyfriend whom she manipulates. She is abusive to parents & grandmother, & has lately taken to damaging walls & breaking things including a mirror. Parents & grandmother are distraught, especially since they can’t get the child to visit a doctor or psychologist. She also frequently threatens them that if they check her behaviour, she will call the cops. Nobody has laid a hand on her, or abused her in any way. Please advise where parents can obtain help. She does not do drugs or drink alcohol.
Teenagers can be dreadfully emotional and stubborn because they are so posses by the moment. In their minds if the their desires aren’t met immediately they may not be met at all. Add to this the fact that when teens can’t win an argument logically they will usually turn to bullying (as indicated by what you have said about the physical damage your niece is causing) and you have people who are very hard to live with sometimes.
In response to a couple of your points: Parent Help Line (13 22 89) is a great starting point for parents in need. For face to face counselling your family could find some great help from Centacare (a counselling service of the Catholic church but open to people of all faiths).
If your niece threatens to call the police, maybe she should be allowed to. If, as you say, there are no issues of abuse the police will very likely reinforce the views of her parents.
Perhaps, though, the other direction to take is to find out why she will not attend school. For a clever girl who is not being influenced by alcohol or other drugs this is an unusual behaviour. It makes me wonder whether there are issues in her life (bullying, inappropriate relationships, academic struggle) that make school a hostile environment for her. Because, for whatever reason she will not open up about those issues she is taking illogical pathways to keep herself from having to confront them.
It is very important during this time for her parents to find some way to maintain and encourage whatever elements of a normal relationship they can. This does not mean giving in to her whims or accepting outrageous behaviour. What it does mean is to be careful to be on the look out for any signs of tenderness or normality she shows and to acknowledge and affirm those. Seek ways to spend time with her away from the tension causing issues. The more that positive side of the relationship can be built up the more likely it is that the negative side of her behaviour will begin to moderate.