How do you unblock a web site from a router?

[Alyssa T]

My husband and I had my little sister over for the weekend and had to block facebook from our router as she is not allowed on, now we can't get it back on, help! I have a netgear router, any solutions would be greatly appreciated.
Thanks, and how would I re-block it for when she comes over next? (Husband usually does these things so I don't remember how he did it.)

[Vulcan]

Look for a small hole on the router, that is the reset button. Or remove power from the router. That will reset it to default. Then just set up any other features that you need like in the beginning