I would offer to help a neighbor or busy mom with household cleaning.maybe helping every weekend (or every other weekend)with laundry,cleaning the bathroom or just random things around the house,cleaning baby toys...cleaning is a great way to help someone and earn some money.

make sure its someone that your parents trust since you would be in someones house without them.

maybe cleaning the interior of someones car and washing the outside.

how do you feel about ironing?maybe you can iron shirts for someone - my mother in law irons her hairdressers shirts for him every week ( he drops them off every 2 weeks )and in return he cuts and colors her hair