Coming from a mental health nursing background, I hope she is strong enough to tough it out, teaching at that school. Those children need a positive role model, something that their home environment does not provide them with. It will take time and a lot of stamina, but once the children build up some trust in her, respect will follow. The abusive language and the hostile reactions are their attempt of self-preservation, the only way they have learnt so far. 

In the past, I have dealt with the aftermaths of such chaotic and antisocial upbringing, having worked as a nurse in a substance misuse team. There was hardly a client with a "normal" childhood. And I often wondered where were the professionals when them kids needed them most. 

I really hope that young teacher will persevere, not all is lost for them children, unlike for their parents. And even if she can only turn the future around for only one of her pupils, she has achieved more than many others before her and it would have been worth all her efforts. Best of luck x