The free tickets work like this. About 3/4 weeks into the program she will receive her maingate pass. She will be able to get up to 3 people into the parks per day on 6 different days. If, on one day, she only lets 2 people in then she forfeits that last person she could have let in and there is no "saving" that extra admittance. There are blackout dates that apply to the maingate though. I'm pretty sure that Thanksgiving is one of those dates but you need an active cast member to tell you exactly what parks on what days are blacked out.
As for the hotels, the discount depends on occupancy, season, and whether she is staying in the hotel or not. Because Thanksgiving tends to be busy I couldn't begin to guess what the discount would be. After you make your hotel reservation she will need to go to whichever hotel you chose at any time before you arrive and show her cast ID and the amount you save will be refunded to you in the same way you paid.