Hostessing on Christmas Day

It sounds like hard work (assuming you're not in tier 4 and it still goes ahead). If you have to get on and make the best of it, just keep everything as simple and labour saving as possible.

I know the feeling of dread. I used to work hard (from dawn to dusk) on the day, with a big family and guests. I preferred Boxing day, when, at last, I could sit down and chat with people!

You are so fortunate to be having a cooked meal delivered by your daughter and being able to share it in your home with family.
If you were at your daughters would you be sitting still whilst she ran around waiting on you?
Yes, YABU

They may be a bit slower, but can probably help themselves, I expect, if you can resist hopping up, I assume your sister manages at her home.