Congratulations!
I won 2 nights at the Grand Californian and four 2-day parkhoppers from the DIS Unplugged podcast 1-year anniversary giveaway (thanks, guys!). No transportation but I only live a state away so that was no hardship. It was
amazing. Honestly, I was seriously excited for weeks after I won, and I'm still so grateful, as I thought I would literally NEVER be able to stay at the Grand Californian.
When I won, I had to choose 3 different sets of dates and then would be booked into one of them--I got my first choice (11/1-11/3/12). There was a bit of a wait, waiting for Tom to hear from Disney about the dates, but it all turned out just great!
Since I could bring up to 3 other people, I invited my friend who was over while I was entering the contest, my best friend from Florida (who flew out), and my mom, who took me on countless Disney trips when I was younger (and still goes with me now!). We actually stretched out the trip by booking 2 more days at the front end of the trip and buying Halloween party tickets for Halloween night...but the DIS Unplugged trip would've been wonderful just on its own too. Having some free lodging also made it possible to entice my friend out here to fulfill her dream of dressing up on Halloween (AS Ariel, AT Disneyland), so it was perfect!
We checked in to the Grand Californian maybe 8:30 AM the morning of the first day of the DIS Unplugged portion of the trip. (Disneyland opened at 10 AM, Magic Morning at 9.) Aside from parking, everything was covered! The Grand Californian had us booked into a standard view/5 person room but asked if 2 queens would be OK instead. I asked if they had anything with a view, the Cast Member worked her magic for maybe 5 awkward minutes, and voila! A partial-pool-view room, I believe in the new/Villas section...and we got into our room at our early check-in! (The bellhop told me not to tell anyone, because that NEVER happens. And I know it's unusual, but here I am, telling you all anyway...

)
The room was lovely, and it was a quick walk and elevator ride to the Paradise Viewing Area! (Which I think is highly underrated, since I never saw another soul there our whole trip.) Even though the tickets and hotel were free, I definitely made the most of the trip. I almost wish I'd spent a little time relaxing in the hotel itself instead of just running around Disneyland/DCA and exploring.
Almost.
I know your dad's girlfriend is family, so it's not necessary, but it might be a nice gesture to buy her a little something as a thank you for taking you along on the trip.