at that age I:
Pet Sit
Shoveled snow - used to pray for snow - not for the day off, for the $$ opportunities
Made "stuff" (little bird marionettes) to sell at a local crafts faire
Was good enough (well, by age 15 or so) to build plastic models for pay (the photos on my web site are of my 'junky' stuff that was not good enough to sell - I never took photos at that time, and wish I did

If I helped out particularly well around the house, I'd occasionalyy get slipped some extra $$ - like the time Mom and Dad decided to rebuilt the entire house - gut the 1st floor to the walls, and redo - Up at 6:00am, working by 6:30, don't stop for 12-14 hours - I'm taliking ripping put plastr/lathing, bagging/boxing, running it out to the garbage, hauling lumber, playing "fetch", helping drag BX cable, etc - That got me a nice donation to my "hobby" fund