She is my 13 year old niece, I am fairly confident she won't be savvy enough with Windows to get around this - famous last words!As feek has said, OpenDNS is excellent! Though if there's no router then it'd be fairly easy to change the local DNS herself, mind you if she's determined enough she'd be able to override pretty much anything.
Call the cyber police
She is my 13 year old niece, I am fairly confident she won't be savvy enough with Windows to get around this - famous last words!