Is this universally true? In the US it appears that it just means there's more restrictions to what types of jobs you can/can't do and the hours you're allowed to work, but AFAIK it's not actually illegal to work as a child.

https://www.dol.gov/agencies/whd/YouthRules/young-workers/no...

Define child. Define labour.

In my justification 14 years can legally hold some jobs.

Are girl scouts going door to door and selling cookies performing labour?

Children unloading and loading the dishwasher at home?