Parental Controls in Ubuntu - per user

Parental Controls in Ubuntu - per user

I would like to set up parental controls on Ubuntu for a friend of mine. I want it so that the child user has the controls set, but the parent user is not restricted. To be clear, they are sharing one computer, so a router based solution won't help. And I would like a set of step by step instructions to do this. Just one way of doing it.