What does that make me?

She had a great time on the flight, and is impressed with herself as a great world traveler.

People need to get a better grasp of risk managment when it comes to kids. You're more likely to kill them by feeding them fast food every day than by letting them ride the subway.

Good for you!! I have friends in Europe who biked solo across whole countries, staying in youth hostels or with friends, in their mid-teens. Kids bike 10-15 miles to school in the Netherlands; when they are small, they ride with parents, but by 10 or so, they're on their own. The kids enjoy the independence, and they grow up less self-absorbed.

I sent my own autistic son to school on public transit, because he could deal better with drunk panhandlers than with malicious kids.

We built the separate school bus system to keep kids safe. They would be much safer from bullying and exposure to toxic schoolmates if they traveled on a well-monitored public system. Our mass transit systems could afford to be much better, and more attractive to all riders, if we all rode together.

I'm not saying 9 is too young to use public transportation. That is an individual judgment call based on the area, the route and the child. But there is a difference between commercial air travel and public transportation. On most commercial flights you are usually required to pay a little extra for an unaccompanied minor, and they are given special attention and assistance by airline staff to make sure they get to their destination safely. There is no such assistance on public transportation (that I know of).