12-year-old me installed Linux on an old desktop tower and I also broke things constantly. The difference is my parents were both humanities majors and I knew full well there was no point in asking them for help. Even at the time, the resources were all there for me to teach myself to Linux. Sure, I spent many many hours troubleshooting things instead of doing whatever it was I had as my end goal, but I was a kid—learning is the point!
It's harder as a parent to know that you're capable of solving their problem and still say no, but by age 12 that's pretty much your primary job: to find more and more things that they can start doing for themselves, express your confidence in them, and let them figure out how to adult bit by bit. Breaking a Linux install and fixing it again is among the lowest stakes ways that dynamic will play out from here on.
It's harder as a parent to know that you're capable of solving their problem and still say no, but by age 12 that's pretty much your primary job: to find more and more things that they can start doing for themselves, express your confidence in them, and let them figure out how to adult bit by bit. Breaking a Linux install and fixing it again is among the lowest stakes ways that dynamic will play out from here on.