I think I had my own computer when I was 14 or 15. Windows 98 SE, it was.
Didn't get the Internet permanently in my room until 16 though. I remember running an ethernet cable across the floor to the other end of the house (where the modem was) when I wanted Internet. Good times, good times.
I'd let my kid have a computer in their room, no problem. I cannot comment, however, on whether or not I would use Wireshark to spy on their Internet activity, though
(I kid, I wouldn't do that.)