Can you log into your router? Usually to log in your just put the ip address of it in your internet browser search bar.
From there check the parental control settings there. If your router does support parental controls you should be able to set times and block websites.
I don't think there's a download restriction though. Sorry
The best your probably going to get is the time restriction.
Kids can be a bare. =P
Should look something like this if you have it. (This is my router which may be set up completely different then yours)