I agree that you should have the final say on where she goes, and to some extent, what activities she will be involved in. But this does not mean micromanaging her life. I was just with a high school senior boy's father last night, and he was taking it upon himself to see whether his son was scheduled to work at the local pool the next day, while his son was fishing accross the road and periodically checking in with his dad on the cell phone to "encourage" him to keep making calls until he found out the answer.
Amazing! I rebelled against my parents at that age, I wanted to be independent- the sooner the better. For some strange reason I was convinced I could manage my life better than my parents and was in a hurry to prove it. I was wrong about that, but kept plugging at it and finally made it work. Many of the kids today want their parents to continue to run their lives for them. Have they no sense of freedom or adventure?