[user104658]

Hmmmm a tough one I think. Both of my kids were "sling babies" - think like a baby kangaroo... they would just be tucked into the sling silently and with my youngest you'd never even have known she was there quite honestly.

I think, basically, with very young babies in that situation it should be fine but on the understanding that if there's disruption then they need to leave and that it'll then be considered a "failed experiment" and they'll need to make other arrangements. But they should definitely get the chance to "prove the theory" - if the mother is saying the baby won't cause disruption, then people should be fine with that until something suggests otherwise . If there is no disruption, what's the problem?