THANK YOU - everyone. I have got over the shock now, she doesn't want to come, well she can live with her (female BTW) friend - the friend is a nice girl, I'm sure that they will cope admitrably, not least because the friend's social worker will keep an eye. The door will always be open, no matter what.
My 17 year old daughter leaves home or threatens to about every couple of months been like this since she was 16, not a lot you can do at that age can't ground em, talk and explain the situation listen to what she has to say (probably mostly insults) and let her get on with it. They soon come back when the cooking and washing starts to get a chore and the money isn't on tap.
Hmm as she is U18 do you not still have a duty of care for her as her parents, legally isn't she still your responsibility, I dunno about the law, but with my 16 yr old she would be moving with us, yeah when she turns 18 she can crack on.