i own a property, pay month in month out for it and yet the house next door that has been bought by a housing association. That house is occupied by a drug dealer, she is also occupying a 3 bed house even though her children are in care following a house fire there.
No-one can help me, but i can help myself by reporting, speaking to the police and the housing association. No-one is going to compensate me for the loss of value in my home or the constant noise and visitors going to and from the house, the language, the violent arguments outside the property etc etc.
I realise that your friend may well be suffering but she has to be prepared to report everytime something happens. If its specific council residents then she can complain about the noise and disruption to the council too.