I know that this is a small point, but I don't want to either spend money needlessly OR get in trouble with the Italian train police :)
Regarding the Express Train from Fiumicino to Termini. It is currently Euro 11. On the Trenitalia website it shows # of tickets for children 4-12 with the price being free. My daughter will be 12 and 9 months when we are in Rome this November. I have seen some places where it says "UNDER 12" and others listed like above which might make me think "Not yet 13."
It would be GREAT to not have to pay the 22 Euros (return)for her if that were indeed the case (more gelato for us!) but I can't get a definitive answer. Anyone travel with a tween before that can help? (or point me to who I could ask for a the "real" answer... as I said, I want to be mindful of money, but will follow the train law as I am certain I'd be one of the 2 people to get stopped by the train police!)