OK found this useful article on how to get this application up and running:
Open a Terminal and enter:
malcontent-control
I have removed access to Firefox so it does not show in Child Account.
If internet is needed (homework) either supervise on your account or let them use Firefox and use something like OpenDNS - there is a free one but have become more commercial - you do get whitelists and blacklists with OpenDNS.