I have similar situation to yogiem's,(actually much worse).
Since my 16 years old dd started going out with this 19 years old boy, she lost entire interest in her work. She has been getting straight As so far. Her mocks results went down to Bs and Cs. When I talked to her teachers (my dd didn't bother to come with me to the parents' evening) all they said was if she doesn't do the work her grades will go down even further. I talk to her constantly, I explain the consequences but this always ends up with cries, shouts etc.Sometimes she does not turn up to school, sometimes she leaves for the afternoon. School tries everything to encourage her to keep up with her work. I have been trying reward systems or punisment as lowering her allowance. She goes out all weekend all I get a text message telling me where she is.(She usually stays with her boyfriend who lives with his family. As a rule she is supposed to be at home by 7.00 pm during the week, but she usually comes back at 9.00, 10.30. I feel so helpless... she also refuses to introduce this boy to us.My main concern is as this boy does not go to school and enjoying family home without working, my dd thinks it is ok to live like that. Recently she is saying that she won't do her A levels. She has Science exam this Monday and I know she will be out all weekend I do not know what to do!!!
Can you give me any suggestions?