Each of our children have found creative ways to earn money. Our oldest had a candy machine, tutored, and did babysitting before she was 12. Our son had a casino machine and repaired mailboxes. Our youngest now decided to give massages.
Her place is quite convenient, right in the house. She accepts all coins (or the occasional dollar), and will focus on whichever area hurts. She employs the "pinch" method as well as the "elbow" method, so sometimes you get what you pay for.