Can you get a job at 15 if you are working with your brother who is over 21?

Both my brothers work at village inn.....good food......good feelings....And I'm 15 and would be delighted to work there with them. One of my brothers is 22 and the other is 19. So I was wondering if there was a law in which this would be aloud. I somewhat recollect of hearing of something like this.......also I live in Colorado.