I'm gonna bore you silly here!!!Firstly I dont know how this affects a child who is running there own business, but I do know about the employment of children.
The working act for children and young persons had some changes made to it in 1989 mailny not allowing children to work in industrial outlets.
You are stated as a child if you are under 16, school leaving age and the working time regulations only allow children to work 2 hours a day on any school day and sunday, 5 hours a day on a saturday between the hours of 7am & 7pm.
During school holidays a maximum of 25 hours a week but you must have 2 out of them 6 weeks for rest purposes.
The employer/ee must look into obtaining a work permit from the education board or though I have found that the child can obtain these forms/permits through there school, obviously these forms need parental consent to.
Children are most definately not allowed to work in Pubs or Betting offices, nor are they allowed into factorys or building sites.
There is a loop hole if you work in a family run business with supervison from parents, but this is something I do not know about.This is where you might get out of after 7pm working reg's.
The reason I know this is that I am an employer in an industrial outlet and I'm not allowed to employee anyone under the age of 16 due to this regulation, (for some time employment only allowed at supervised shop floor level for 15 year olds with permit) nor can I employee under 18's if they are to operate machinery or do any injury to themselves through lifting carrying etc in the H&S act.
So if you do take up dj'in or just get another form of employment I hope this has helped.
Are you all still awake?