Quote from Mary Cooper in the episode Thanksgiving
Georgie: While I'm here, I wanted to let you know we're gonna come to your place for Thanksgiving. Mary Cooper: Oh. I'm not doing Thanksgiving this year. Georgie: What are you talking about? Mary Cooper: Well, Sheldon's in school, and Missy got invited to a friend's. Georgie: Well, she can't go. It's Thanksgiving. Mary Cooper: I already told her she could. And to be perfectly honest, I don't feel like celebrating. Georgie: But this was Dad's favorite holiday. Mary Cooper: I know, and doing it without him would just be too hard.