Teenagers need restrictions in place and guidance; the part of their brain that deals with risk isn't fully developed until much older. Being left to their own devices at that age isn't the smartest thing to do, but we've discussed on here previously that some kids are out of control at that age, and the only way they seem to learn is from their own mistakes.
I grew up in a similar household, and I look back over my life, and I'm lucky to be here. Add another level of complexity to PB's case, with her gender.
I can recall I skipped school one day with a friend who was 2 years older than me (13 and 15), we decided to ride our bikes to a swimming hole as we had done many times before. So that our parents didn't know we had been swimming all day, we decided to go swimming in our underwear as it takes much less time for them to dry. As we're swimming, an older man turns up in his 40s and starts talking to us, and the conversation turns to, "do you want any beers?"
Not sure what got into my friend's head but he said "yes", the man asked him to get the beers out of his car that was parked about 40 meters away. I was still in the water at this point, this man strips naked and comes beside me and says, " it's OK you can take your underwear off if you want to". As soon as I heard this, my gut feeling said something was bad and I got out of the water. If that guy wanted to, he could have overpowered me and drowned me in a matter of seconds.
My friend drank the beer, and soon after we left. In his household, it wasn't uncommon at the time that adults would offer him a beer. I think the size of my friend may have been a deterrent for this man, but things could have ended much worse than they did that day. No one would have even known where to look for us, because we never told anyone where we were.
"Risk taking increases during the transition from childhood to adolescence due to the changes in the brain’s socio-emotional system, following puberty. This period is marked by heightened reward-seeking and sensation seeking, especially in the presence of peers, driven by a significant remodelling of the brain’s dopaminergic system, which is crucial for emotional and motivational regulation (Steinberg, 2008)."