For these reasons I totally trust her more then I trust my older daughter so that's why I say it's not about age, it'sa state of mind. our daughters come in contact with boys at school or wherever so naturally they will want to explore..
I don't think age is much of a factor as is their individual state of mind and maturity level.
For instance my older daughter maintained A grades from Pre-school to High school and was even valedictorian, she's got 3 jobs, in college and very responsible, kind and giving to everyone but when it comes to boys her judgement is off..
He cannot text or use his phone while driving my daughter.
If I call her cell or text her at ANY point she must answer immediately.