I can not let go the following go without mentioning something:
"It can be terribly difficult to travel with small children in the UK; as a society we're generally very unwelcoming to parents and children unlike on the continent, "
Yes, but in the continent, children "belong" to society, everybody is free to make them laugh, help with them, pat their heads and tell them off if they are misbehaving.
Parents are more willing to accept that they are responsible for the safety of their own children, and that any favour in offer is just that, a favour. IE. in this case, they may have warmed the milk for you but they wouldn't accept any responsibility if you burned the child with it, if it became contaminated during the process, etc. etc. t If that happened would be your sole responsibility, as you should have checked. They may have taken the time to warm the milk and probably the other 20 people in the queue would be relatively happy to wait for 40 minutes for a coffee, as the waiter was busy offering a personalised free service.
Many continentals laugh about our health and safety policies claiming that we are removing the responsibility from the people to take care of themselves. Someway I think they have a point...