negociation with your D.

It's ok for her to go to party and have a boy friend, but you can ask for return which is her GPA has to be like 4.8(5.0 is perfect). When my son is in HS, he spend nearly 20 hours /week in sport. He had a girl friend and they went to partys. But if his GPA drop to 4.6, I granted him from all those activitys. this way, he work hard and play hard. Learn time manage skill which very useful in college.