I've only spent Christmas day alone once and that was in the pandemic when my trip to my DD in Scotland had to be cancelled as we were only allowed one day together. DS and his family were living abroad, so we had a zoom lunch together. Unfortunately my technology failed and by the time I'd got it working my dinner had gone cold!
I knew someone locally who I thought would be alone and asked her what she was doing as I thought I could cook her a meal and take it round as I knew she had limited cooking facilities. Turned out she had been invited somewhere - not sure if it was allowed under covid rules - but she turned up on Christmas eve with a 'reduced ready meal roast dinner' thinking I didn't have any Christmas food! She had completely got the wrong end of the stick. She couldn't use the food herself as she only has a hob to cook on - no oven or microwave - but I couldn't use it ether as I'd bought Christmas food for myself. All very embarassing!
Actually being alone wasn't as bad as I'd expected, though I did have a good cry when I found out the trip to Scotland was off. DS had sent a hamper to DD's address for us to share for Christmas so DD had to consume it all alone! I seem to remember she kept me a few treats which would still be in date when we were eventually able to get together.
I'm sure your friend will appreciate a call or zoom session and the rest of the day she can do whatever she likes.