You can use a site like openDNS to block facebook and any other site you want from your daughter, it just requires some setup and a free account.
http://www.opendns.com/
Click the tab "Use OpenDNS" and follow the instructions.
Afterwards, Click "Create an Account", and go through the process.
Then go to the Dashboard (at top), and click the settings tab.
Here you can choose to block preset websites, or block ones you choose.
You can also opt to block ones you really choose and not from a category by looking under "Manage individual domains".
Choose Always Block, and type in a web address, and click add domain.
Give it time, and soon that website will be blocked and a page returned by OpenDNS telling it was block by an administrator.
Any questions, shoot me an email.
Note: This might not work for certain reasons, at least ones I don't know.