Avoidance is worse. You have to look at this issue straight on, stop listening to what others are telling you, and deal with your situation. In my opinion, it is better not to have a 14 year old girl give birth than it is to have her do so. I do not condone teenage sex, but if you believe that it is a strong possibility, then physically do what you can to physically protect your child. Birth control pills and condoms for pregnancy prevention and disease prevention.
I know it's sobering and scary to confront these kinds of issues with our children, but there is a scarier level ~ dealing with grandchildren coming into this world way before it is time, or worse than that, std's.