Just forget about this "gift". It means nothing unless there is a boatload of traffic to it already which I highly doubt. You were given access to a sub-domain.
It will probably expire as soon as the owner stops paying for it. Only the host and the owner knows how long that term is.
The domain name seems to be registered till April 05, 2007. The person registering the site used false information (name and address info), so it may be terminated at any time according to GoDaddy policies.
You might want to start looking for a new host and domain name....
Ron
getting your own domain name is cheap, around 10 $ per year. and getting a host .. 5 $ or less per month, so it's not much of a big investment, compared to what could happen if you work on it and then goes down.