I'm so sorry for the situation in which you find yourself. Are you still at school? If so, talk to your Head Teacher or another teacher you trust and see if they can help you or refer you to some sources of help for her. If you've left school, maybe somebody at your GP's surgery can put you in touch with some Counselling or Drug Treatment facilities who can offer help. The only other "tough love" treatment I can think of is to ring Crimestoppers anonymously on 0800 555 111. and report her heroin use. This sounds a terrible thing to do but if the police get involved it might shock her, bring her to her senses and help get support agencies involved who can help her to change her ways. You sound as if you may be too young to have to carry this horrible burden alone. Do you have afather, or any older relatives or grandparents to whom you can turn for support?