just look around your neighborhood for old people who need their leaves raked or garage cleaned or something. Usually they'll give you like $80 for 30 minutes of work or pay under minimum wage. It is a risk, but more often than not it works out.
Depends where you live. In the US, you are able to hold a job until around age 14 to prevent child worker abuse. I would say that your brother could go around the neighborhood for any jobs they can do.
You don't pickpocket Americans, we beat the living stuff out of pickpocketers (not joking, several countries have warned civilians about pick pocketing Americans)
When I was 14 I saved up enough money over the summer to buy a pc by mowing my neighbors lawns. If you live in a place that has it shoveling snow is also great
(nobody knows about Braum's outside of my area anyway)
In my state you can not work until you are 14