11 year old lies

counseling didnt help. I now have to follow her around and not let her hang out with her friends(unless I'm there). the only time I cant be around her is at school. I dont know what to do. grounding doesn't do anything.

today I checked her backpack and pulled out a test that the teacher has written "retake" on, I asked her about it and she said "I asked you if I could stay sometime after school last week and do a retake and you wouldn't let me".....no, no I didn't say that. I told her" I would never not let you do somthing this important. ever. that's enough lying"

..anyway a small example of the things she lies about. there has been *I think a few* incidents that I haven't been able to catch her in like this one BUT I just can't trust anything she says anymore.