This is a pretty funny image because the kid looks like they're 8 and in full uniform, but there's no way to know their age from this picture. They could be like 14, and a part time job at that age (or a bit younger) isn't weird.
What's weird and, frankly, extremely fucked up is some internet weirdo taking creepshots of a minor and posting it on Lemmy. What the fuck is wrong with you, OP? How would you feel if someone was posting pics like this of your kid on the internet?