John is right, unfortunately.
However, there is a way around it.
they don't check children's ID when you buy their tickets, although they do check pensioners.
when your kids are over sixteen, just buy them a junior ticket.
When you come through the turnstiles, the steward guys stood behind them are checking to see that people are OAPs, kids etc.
So continue to dress your kids in short pants, give them dummies, maybe even carry them. they could bring a trike even to really look effective.
I know it will be a pain making sure your lads shave and making sure your girls wear baggy jumpers (hint: try a Peppa Pig or Winnie The Pooh jumper).
But it's the only way you are going to see the Blue Revolution as it happens.