She probably scheduled for when people would be with family. Does she not have family?
Some of us are far from family. Holidays can be painful.
Some of us do not have family left. Or they are in other states & countries. Or are estranged from them for one reason or another.
At about her age both my parents passed away within 6 months of each other, my one brother was already gone and the other in prison (not that I’d want him at Thanksgiving...but ... family).
Now I am much older, never had children of my own and Thanksgiving this year after working the day was a ham sandwich. I texted friends Happy Thanksgiving wishes, but yea..it is a very empty holiday. Or just another day really. Christmas really won’t be much different either.
But then I have come to really like my quiet Christmas Eve in church and coming home to a Silent Night. And yes, I will work Christmas Day as usual to keep my mind off the emptiness and try to convince myself I work so others can be with their families as there will be a time when some of them might not have family around anymore.
Always be nice to people working the holiday, you just don’t know their whole story.