Saturday jobs for 15 year-olds

[CrosswordAddict]

My friend's DD is 15 and will be 16 in August. She is doing GCSEs this summer and would like to do a Saturday job this year. How old do you need to be for a Saturday job? Also how old do you need to be to babysit?

You can be employed at 13 but there are strict rules on working hours, I think it is only 5 or 6 hours.
At 15 they can work 6 hours. I have a 16 year old working for me in a shop (serving coffee as well as we are a coffee merchant) she works four hours on a saturday.
There is plenty of info on rules on the hmrc website
Not sure about the babysitting thing?

A lot of employers won't take you until 16 because they can't get or won't pay for employers' liability insurance for youngsters

Many of the 'big' employers (supermarkets etc.) won't take on young people without a N.I. number. DD did a stint at Sainsbos and had to wait for that IIRC.