The Mexico City airport is as nice as most in the states and is nicer than some (the awful Las Vegas airport comes to mind). There’s not a lot for kids to do, just the typical shops and restaurants and stuff.

Aeromexico is a good airline. I’ve flown it a few times and they are fine. Better service than most US airlines.

One funny thing about the Mexico City airport is that there are these huge 20 foot billboards lining the roads in and out of the place advertising expensive consumer goods, high end real estate and financial services. If you look closely, you can see cracks between the billboards and behind those are some very poor and run-down neighborhoods.