Dan, I have a two daughter's in their early 20's now. I've gone through the same thing twice! Sounds like you got started off on the right foot. Once my girls got brave enough to bring one home to meet dad I took him to the gun range. Didn't make any threats, just a fun day at the range. They got the point after looking at my target.
I always had a house full of teenager's, my place was the most fun to hang out. I always fired up the grill and feed them. They knew they would have a blast as long as they followed simple rules. If Dad was home the boys could go in the living room and kitchen. If Dad wasn't home the boys stayed outside.
You started GREAT!! I was once told there were only two kind of people who knew everything there was about raising kids. "Those who didn't have any and those who had one and got luckily."
Just be an active part of her life and get to know her friends as much as possible.