I also knew very early on. lol. My difficult child is my middle child, and he was a handfull from the time he hit 2 years old.
By the time he hit 13, he was at a fork in the road and unfortunately, he took the wrong route. He was a good student and athlete, though still getting in trouble, but he chose to drop out of sports and started with the wrong crowd and pot. It was a turning point. I always wonder if there was anything else we could have done that we didn't do that would have made him choose the other path - but I honestly can't think of a thing. We were always there for him, we were considered strict parents, we were involved in his life and in his sports (my husband either coached or helped coach his teams).
All I can suggest is to try to stay involved, and try with everything you have to push them in the right direction. It might or might not help, but at least you'll be able to not have the internal battle about the "what if". difficult children and hormones can wreak havoc on a family.
Hang in there.