How Can a 13 Year Old Earn Money?

you mentioned mowing gardens had failed but we had a young kid came round our house with his own electric mower and we paid him to do the job. He didn't have to enter our house at any time and provided the mower himself so there were no trust issues to be had. It was all very simple. Another similar thing would be washing cars. You could either go round your neighbourhood or set yourself up in a carpark in a large shopping centre and ask people that way. There's one more idea which is seasonal which involves knocking on doors when it snows and clearing paths/driveways etc with your own spade which is always a good one. Good luck!