Yard work is probably your best bet. You could also check to see if any of your neighbors need their house, fence or shed painted. But be prepared to work!!! More jobs will depend on you having a good reputation so getting busted selling drugs will not help you.
Sorry to hear that you need to do that, some places will hire at 15. I started at the mall when i was 15. If not u can baby sit, deliver papers, yard work maybe walk dogs.Sell some stuff on ebay. Good luck :-)
I am sorry a fifteen year-old has to support a family. I started a very successful lawn care and made around twenty thousand and went to school at the age of fifteen. Every year it excelled beyond the point of ridiculous. However, I would strongly, strongly, suggest that he/she attain a four year college degree. This will support the family for years to come. (the government is begging for students)