Outside of MLN serious parental controls are needed for the little ones.
Another reason I like Norton.. they have very customizable parental controls.
How many hours a week does she have for PC non school stuff?
PARENTAL CONTROLS ARE EVIL. Get an adblocker. enable google's safe searches. DO NOT use parental controls - they cripple your computer forever.
and as for your second part of that, whenever she's not doing something, and mom doesn't say "get off the computer"

Wow you are the first person that says not to get parental controls that I know, I guess it is because you might have had parental controls on your computer when you were younger and hated it.