Talking to my friend.

My friend said that despite the fact that she's over 17, her school forbids her from getting a job, and that people tend to start working at a later age in Japan.

How can I tell her that in my country, it's completely different. That it's quite common for people as young as 15 years old to work in places like Mcdonalds and Supermarkets?

Just tell her that. By the way, it's also common in Japan for 15 year olds to work at McDonald's too. It's just "her school" that forbids that. She probably goes to a strict private school.

It's just that my friend was talking about ニート the other day and said that it was a big problem in Japan because people who don't get into high school are too young to work. Maybe she was talking about full time employment.

ニート is NEET. The term invented in Britain due to the huge problem that is occuring there and, now, in many places of the world.

In Japan, people who are in senior high school age have the legal right to work.

I'm sorry, as much as I would like to help you, I'm not sure if I understand your question. What would you like to know exactly, and why can't you ask those questions to your friend?