This has never been enforced on AA. My kids are now nearly 14 and just turned 11. They have been flying together in coach with us in biz/first on both domestic and international flights since they were 7 and 10. Noone has ever said boo to us at checkin, boarding or on board, other than a few flight attendnats coming forward to tell us how good they were. We put them in the first row of coach (if not an exit) and we sit in the back of biz on international or first on domestic. On AA we usually are paying for my ticket and the husband's and he's using EXP upgrades for us and miles for them. The girls are experienced flyers, generally very quiet kids- both are avid readers, and every time I peek back they are engrossed in their books or doing homework. We do not walk back and forth, we go back maybe once a flight, usually to give them some of our unwanted snacks, and they never come forward.