Maybe your mum is like my dad, She probably might of done it via the router control panel, I suggesy you try and gain access to the Router Control panel and browse around and see what ports have been blocked.. If that suceeds, You might be able to unblockany IP's which have been banned via the router.
Hopefully you will be able to acces it.
Or, You could do what I done. Watch your mum/dad or anyone login to their account who have Administrative Rights and remember their password. Once they log off, You login and then you Open up Control panel & go to user-accounts and change your oneto Admin Status. Then, You log back into your account and change all other Admin Accounts to 'Limited User' and then change your password. This should succesfully piss off your mum enough to get rid of the Parental Controls, And if this continues to happen.. Just do the steps over and over again. It will work eventually

Regards, Valency