To be completely honest, I myself am not a parent so my answer might not mean much. But i think you're lucky they waited that long. There are so many girls who are 13 and such having sex with a whole bunch of guys. My advice would be talk to her about it and get her on some sort of birth control. I'm sure you'd much rather have her safe then end up with her being pregnant at age 16. And warn her about STDs and if you know someone with one have them talk to her about it. I think that would really help so if her and her boyfriend break up she doesn't think she can have sex with whoever she wants.