she left a 12 year old in charge of a three year old at the mall which is a much different situation.
"Children under four years of age may only use public transport if they are accompanied by a person who is at least six years of age."
https://www.bvg.de/en/Tickets/fare-overview/conditions-of-ca...
They might be able to stop the infant from killing themselves, it depends a lot on the 3 yo. In our case the eldest is over-protective mostly, except when bored or distracted ...
I think you've overstretched with that claim.